Using sites like Craigslist, Twitter and YouTube, the researchers were able to cross-reference information contained within publicly available online content to determine the exact home addresses of potential victims, even those who had posted the content anonymously. The experiments didn't take weeks, days or even hours of research either - the addresses were pinpointed with GPS-level accuracy within minutes.

The original report, "Cybercasing the Joint: On the Privacy Implications of Geotagging," by researchers Gerald Friedland and Robin Sommer, was published in May and is due to be presented at the upcoming USENIX Workshop on Hot Topics in Security next month, reports trend-tracking site PSFK.

The report's authors examined in detail the rapid spread of location-based services, which have spread in large part due to the growing smartphone market. Today's mobile devices and their accompanying applications tap into a phone's GPS or use Wi-Fi triangulation to append geotags, or locational information, to the items recorded with the phone, whether that's an update posted to Twitter, a photo uploaded to Flickr or a video sent to YouTube.

A major concern with these types of applications, say the researchers, is that many consumers don't know such information is being shared, especially on a such a large, public scale. For example, Apple's iPhone by default embeds high-precision geo-coordinates within all photos and videos taken with the internal camera unless explicitly switched off in the phone's settings. The accuracy of these geo-coordinates "even exceeds that of GPS," warn the researchers, regularly reaching "resolutions of +/- 1 m in good conditions and postal-address accuracy indoors."

But publishing these precise geo-coordinates embedded into the shared texts, photos and videos to the Web is only part of the problem. Also troubling is the fact that the large amount of multimedia now available online combined with easy-to-use search tools for sifting through geo-tagged data makes it possible for anyone to easily launch systematic privacy attacks. In addition, services like Google's Street View and other annotated maps help simplify the process of correlating findings across several independent resources.

In other words, it's not just that the geo-tagged information is online, it's that there are a plethora of tools with which to analyze it.

Cybercasing via Craigslist, Twitter, YouTube

To demonstrate the ease involved in determining a stranger's precise location, Friedland and Sommer first "cybercased" Craigslist, a classified ads website often used to post items for sale. Here they found geo-tagged photos that they compared with Google Street View, allowing them to determine the postal addresses belonging to the item's sellers. Even more helpful (if the researchers were, in fact, thieves), was that several ads included a "best time to call" - implying the hours the sellers were not at home.

In further tests, the researchers cybercased Twitter, which allows mobile users to geo-tag their updates. Third-party applications - like TwitPic, for example, used for posting images to Twitter - also include locational data. Using a Firefox Web browser plugin called Exif Viewer, it was only a matter of right-clicking on an image to reveal location of the Twitter post, plotted on a map.

A third experiment, and perhaps the most devious yet, showed the ease with which this form of cyberstalking could be automated. While the above examples revealed users' location within minutes, manual effort was still involved. For YouTube, however, the researchers wrote a simple script that automatically recognized when videos were recorded a certain distance away from a primary location, that being the potential victims' home addresses. When the "vacation distance," as it was called, was set to 100 KM, the script returned 106 hits revealing who was out-of-town in the test location of Berkeley, California. After briefly perusing the results, the researchers came across a video from someone who was clearly on a Caribbean vacation and would have made an ideal victim.

Solutions?

The paper's goal was not to provide solutions, necessarily, for this digital era problem, but to raise awareness. Although the researchers did suggest a couple of interesting ideas, including a mockup of a mobile-phone dialog that would provide more control over geotagged photos and thoughts about privacy controls within APIs themselves, there aren't any real-world fixes yet. For now, only user education and research into better systems for privacy protection is suggested.

But may we offer, perhaps, a simple fix to address some of these concerns: don't post your vacation photos until after you return home and don't Twitter about it while there. Simple steps like these could go a long way into protecting your home and valuables from being "cybercased" by any tech-savvy thieves. 

For a real-world example of how Newsmap works, you can visit DailyRecord, a news site which features an embedded "news map" at the bottom of their homepage. For another example of a similar technology, see Bing Maps's Local Lens application, a map layer that identifies news stories by city and neighborhood and maps them out using the Bing Maps service. (Bing Maps does not use MetaCarta's technology, it's just similar.)

Although news maps like those above are somewhat interesting, the most intriguing thing about this new acquisition is not the map app, but the technology behind it. Basically, the geotagging aspect to the MetaCarta service can add location data to existing information that previously had none. In doing so, a company could build up a geo-database that could function as the backend for all sorts of location-based services from social apps to local search tools and more. And the need to have an accurate, rich and complete geo-database is going to be a key component to winning a top position in the emerging location-based services market.

Nokia hasn't specified exactly how it plans to use the newly acquired company's technology, only saying that "MetaCarta's technology will be used in the area of local search in location and other services." It's not a leap, though, to assume that MetaCarta's technology could be integrated into Nokia's free Ovi Maps mobile application.

Nokia has had a clear focus on location-based services as of late. The company acquired the social travel service Dopplr in September of last year and later launched turn-by-turn navigation for Ovi Maps in January. However, the company's largest mapping-related acquisition to date is still the $8.1 billion purchase of digital map provider Navteq in 2007.

While the iPhone app supports both Wordpress.com and self-hosted WordPress blogs, users with self-hosted blogs won't see any advantage in geotagging their blogs until WordPress releases its own geotagging plugin in a few weeks.

Geotags are Only Exposed in Your Blog's Feed (For Now)

For now, it doesn't look like there is any way to actually highlight a post's location directly in a post or on the blog, though WordPress.com's feeds are compatible with the GeoRSS format and the location attached to a post will appear in compatible services like Friendfeed. It would be nice if WordPress automatically added a link to your location on a map at the bottom of the post or gave you the option to display the location associated with this post in a sidebar widget.

Chances are, WordPress will do more with this in this information in the future. It would be nice, for example, if WordPress could highlight "nearby" posts or allowed users to browser post on a map.

How To Enable Geotagging in WordPress

By default, WordPress won't show your location, even on geotagged posts. To enable geotagging on Wordpress.com, you first have to enable it in the Wordpress.com settings for your blog. Look for the "Enable Geotagging" setting in the "Your Profile" tab.

To geotag your post from the iPhone app, simply click on the compass icon next to your new post's headline.

Don't miss the ReadWriteWeb Mobile Summit on May 7th in Mountain View, California! We're at a key point in the history of mobile computing right now - we hope you'll join us, and a group of the most innovative leaders in the mobile industry, to discuss it.

Brazil now accounts for 8.8% of all Twitter users - up from just 2% in June. Indonesia's Twitter users now account for 2.5% of all users (up from 0.5%). The percentage of German users among all Twitter users is now 2.5%, up from 1.5% in the middle of last year.

Users from Brazil now represent Twitter's second most active population, followed by the U.K. (7.2%), Canada (4.35%) and Germany (2.49%).

Interestingly, the U.K. still leads Brazil when it comes to the number of total tweets contributed. Here the U.S. leads with 56.59% (down from 50.9% last year), followed by the U.K. (8.09%). Twitter's Brazilian population contributed 6.73% of all tweets.

Twitter's most active users can be found in New York City, London and Los Angeles. Twitter's hometown of San Francisco is home to the company's 10th most active group of users.

These numbers clearly indicate that Twitter saw significant growth outside the U.S. over the last six months. You can find Sysomos' full report here.

Nobody is Using Geotagging

Sysomos got this this data by analyzing the profiles of over 13 million unique Twitter users who were active between Oct. 16, 2009 and Dec. 16, 2009.

Given the recent interest in geotagging and geolocation services, we also asked Sysomos to look at the percentage of tweets that are currently being tagged trough Twitter's Geotagging API. While we didn't expect that large numbers of users were currently attaching location data to their tweets, we were surprised by how low this number currently is. Sysomos scanned 10 million tweets from Monday and Tuesday this week. Only 0.23% of these had been tagged using the Geotagging API.

Given that the API has only been available for a few month and that only a small number of Twitter clients currently supports this service, it doesn't come us a surprise that only a few users are currently using this service. This small number, however, also indicates that users aren't clamoring to tag their location to their tweets.

It's important to note that the Mixer Labs GeoAPI is not tied to Twitter. GeoAPI offers tools like a reverse geocoder that can take GPS coordinates and turn them into human readable information and a service that can find media files and status updates related to a specific place on Flickr, Twitter or YouTube. Mixer Labs also offers an iPhone SDK. Judging from Twitter's announcement, the GeoAPI will continue to work while Twitter figures out how to best integrate its current geotagging API with Mixer Labs' GeoAPI.

GeoMeme is Hitching's side project, a real-time web app and also a location-aware mobile web app for iPhone and Android phones. It allows users to see and compare trends in specific locations; for example, you could see the most tweeted-about musicians performing at an award show or the most-tweeted political buzzwords in a given state or town.

GeoMeme then measures and compares the number of matching tweets within the stated geographical area based on public data from a number of geotagged tweets from mobile Twitter apps.

For example, on this Sunday evening, we can see that the Vikings are beating the Bears... in Twitter mentions in Minneapolis, at least:

The app might also be interesting for brands. We can see here that legendary local burger chain In N Out wins over Carl's Jr. in Twitter mentions in Los Angeles:

We can also use the app to check the pulse of holiday revelers in New York City:

It would be even cooler to see a sentiment-measuring feature; i.e., I'd like to compare tweets of the terms "liberal" and "conservative" in Virginia, then see what percent of those tweets were negative or favorable. Not all mentions of a given term are going to be good ones, after all.

Take GeoMeme for a test drive in your town to see what your neighbors are tweeting about, and let us know your thoughts in the comments! Do you think that with more development, GeoMeme could be a useful tool?

Typical of what we like to think of as the company's "mysterious charm," the feature has been unveiled six months later with a brief post on the Twitter blog. The new geotagging capabilities can already be seen in certain third-party apps and might even come to the web interface sometime soon.

Apps such as Birdfeed, Seesmic Web, Foursquare, Gowalla, Twidroid, Twittelator Pro, and many others are already supporting location-based data for tweets.

"The added information provides valuable context when reading your friends tweets and allows you to better focus in on local conversations," writes Twitter platform/API man Ryan Sarver in the blog post.

"Now you can find out what live music is playing right now in your neighborhood or what people visiting Checkpoint Charlie are saying today about the anniversary of the Berlin Wall. These are only the beginning and we are really looking forward to seeing the creative uses emerge from the developer community."

As are we! But we might hold out on enabling the geo-tastic feature just yet. We've still got a few stalkers to shake, and we're waiting for the inevitable bugs to surface before we trust our favorite microblog with our favorite haunts, too.

For services that already offer support for geotagged information, including FriendFeed, for example, Pixelpipe will just use those services' native APIs to pass the information along. Pixelpipe already offered this feature when users uploaded geotagged media files, but now, the service will also enable this function for text-based status updates.

We know that Twitter will soon enable its geolocation API, which will hopefully enable a whole range of new services, so for Twitter users, this is really just a stop-gap measure and there are already a few other services out there that offer similar features for Twitter. For now, however, if you want to send text-based status updates to multiple services, this is the most convenient way to include geolocation information with your status updates.

Flickr, which hosts a rapidly increasing number of photos, is increasingly using location as a means to organize photos. Earlier this year, for example, the company announced that it now hosts over 100 million geotagged photos and in order to make this data more accessible, Flickr also unveiled a new 'nearby' page on its web site, which displays a map with images that were taken close to another photo.

Flickr's mobile site is also becoming an increasingly valuable asset to the company. Last December, Flickr announced that traffic to the mobile site had increased by more than 50% over the last year, and it has made various smaller updates to the site since then. As smartphones become increasingly better at taking pictures and surfing the web, it is good to see that Flickr is bringing these two worlds together nicely on its mobile site.

Comments would be a very interesting addition to Twitter, as they could basically constitute a replacement for the use of the @ reply. Other micro-blogging services like Plurk or the new defunct Rejaw used comments and they make it a lot easier to keep track of conversations.

Scoble also got a chance to chat with Anamitra Banerji, who is actually working on Twitter's commercial products. Banerji confirmed that Twitter is indeed trying to stay away from advertising based revenue models and is looking to sell data and features to businesses instead. Twitter believes that consumers are not very likely to buy premium features.

Global Coverage, 21 Languages

While this might seem like a simple task at first (just look for references to 'San Francisco' or 'New York City'), Placemaker actually uses very sophisticated analytics to disambiguate which of the 39 Springfields in the U.S. a text actually refers to. To do so, Placemaker, will, for example, also look for colloquial names for bridges or references to streets and local sights in a text. As many texts obviously contain references to more than one place, Placemaker will often return more than one location per text, though it will try to determine the location.

While Placemaker's database covers the globe and will work for texts in 21 different languages (including texts using double-byte character sets in Japanese, Korean and Traditional Chinese), it will - at least in this first iteration - work best for texts in English, French, Italian, German, and Spanish.

Opening Up The Deep Geo-Web

Yahoo is trying to make this service as open as possible, and there is, for example, no formal rate limit. As Bell told us, Yahoo wants to help developers to open up what he called the "deep geo-web." In many ways, this new tools also fits in with the general strategy of moving away from a "web of pages to a web of objects" that Yahoo announced yesterday.

GeoPlanet for All

In addition, Yahoo also announced that, starting today, it will allow developers to download and use the full data set of Yahoo's GeoPlanet. The GeoPlanet data, which contains information about millions of placenames in multiple languages, also forms the basis of Placemaker's geographical knowledge.The GeoPlanet data will be licensed under the Creative Commons Attribution license.

According to Bell, Yahoo is looking forward to seeing what developers will do with this data. Placemaker is definitely an interesting addition to Yahoo set of geo tools like FireEagle and GeoPlanet, and we are also looking forward to seeing how developers will make use of these newly available tools and we are hoping to see more of Placemaker in Yahoo's own tools as well.

Bliin

Bliin is a Dutch service that combines the location sharing of Google Latitude with the journey recording of Nokia's viNe application (our coverage). With Bliin, you can explore the world around you, zooming in and out on the map while viewing geo-tagged photos, the last recorded locations of other Bliin users, and even the live movements of anyone sharing their journeys on the network. So why isn't Bliin catching on? Blogger Martin Bryant theorizes it could be because the network doesn't integrate with your address book the way viNe or Latitude does. It's also a much smaller European company without the financial clout of either Google or Nokia.

Toaí

Toaí (Portuguese for "I'm Around") is actually a new social network which, at first, appears to be just like any other: you sign up, create a profile, etc. However, Toaí also asks you for your mobile phone number which it uses to text you with music, art, and stores that are near where you are. The recommendations it sends are based on you and your friends' favorites. It also lets you know when your Toaí friends are nearby. Toaí is a great example of how a social network can add in location-based features to take networking beyond the virtual world and into the "real" world. Unfortunately, there is no English-based version of Toaí yet.

Parallel Kingdom

Who cares what your friends are doing when there are dragons to slay, enemies to fight, and weapons to upgrade? The new RPG (role-playing game) Parallel Kingdom for Android and iPhone uses location-based networking to let you see other nearby players on a Google map. Also, when finding monsters to battle, you have to physically move to a new location to do so. The end result is a mashup of traditional gaming and geocaching. (U.S. Only)

Radar

Outside.in's new iPhone application Radar (not to be confused with the photo-sharing iPhone app also called Radar) delivers location-based content including news, blog posts, and tweets to your iPhone. Once installed, the app will geo-locate you upon being launched to deliver the news within 1000 feet of where you are standing, from your neighborhood, or from the entire city. You can also load up Radar with profiles for various locales, including your home, office, and more. Shake the app to switch from the news listings to the map view. (U.S. only)

Flickr already allowed third-party developers to search for photos within a certain radius, but regular users could not easily access this feature from within Flickr.

Besides the default settings, you can also choose to only see pictures taken by your contacts, or images that were taken at a certain date, and within a certain radius from the original picture.

You can access these 'nearby' pages by either adding '/nearby' to the URL of any image that has been geotagged, or by first clicking on the map link under 'Additional Information' and then 'See nearby photos and videos.' It would be nice if Flickr made it a bit easier to access this feature by just adding a link from the actual photo page.

In the announcement, Flickr also explains a number of more advanced query parameters that you can use to find nearby pictures, and it will be interesting to see what third-party developers will do with this.

This is definitely a cool new way to explore Flickr's photo collection. By default, there is a certain degree of randomness to which photos you will see, which makes using this new feature even more fun.

Flickr, by the way, celebrates its 5th birthday tomorrow and now hosts over 3 billion images.