"We're currently pushing out password resets to users who signed up for 3rd party follower-adder sites linked to suspicious behavior," Twitter said earlier today on the account it uses to gather and spread information about spam, @spam.

These applications and the methods they use violate Twitter's terms of service, and using or promoting third-party sites that claim to get you more followers is explicitly verboten.

Some Follower-Adders Bypassed Authentication

Third party applications are supposed to use the Basic Auth or oAuth authentication protocol that allows users to approve an application to act on their behalf without giving up their passwords.

But some adder-follower applications ask for a password directly from the user. Users who do this won't be able to remove that application from their Twitter accounts - instead, they must manually change their passwords in order to cut the application off.

Suspicious Behavior

Twitter warns that such applications can post "duplicated, spam, or malicious updates and links, send unwanted direct messages, aggressively follow, or violate other Twitter rules with your account," all while collecting low-quality followers that are bots or abandoned accounts.

Twitter spokeswoman Carolyn Penner sent these statements:

We forced a password reset for users who previously gave their password to sites that did not use oAuth. This means that these sites had their password and could do things like make people follow or unfollow accounts, or automatically send spammy Tweets on their behalf without their knowledge. We emailed these users to let them know about the password reset and to warn them that they shouldn't share their password with other sites in the future.

Resetting passwords is one of the tools we use to protect our users, and we do this on a regular and ongoing basis.

This time, the vast majority of password resets were pushed to users who gave their password to follower-adder sites; however, there were some users whom we believe were compromised through other vectors.

Should Follower-Adders Be Banned?

But an informal survey on Twitter reveals mixed feelings about this particular breed of spammer. ReadWriteWeb co-editor Marshall Kirkpatrick asked whether people who use "buy more followers" programs should have their Twitter accounts suspended, and got a range of opinions, including:

@Ed: Yes I do, because they get hacked and inject malware into the system. (But if I told you who's used them, you'd faint)

@sophware: Judging a Twitter experience by # of followers is sad. We're all essentially following each other. BTW - what is the violation?

@graubart: if people want to throw money away - let them. There's no benefit to those you pay to acquire

Both the DM email service and the keyword-based spam-blocking feature look like excellent ideas. In addition to blocking spammers to your account, SocialToo will also alert Twitter's @spam account whenever you block somebody and flag them as a spammer (TweetDeck, we should note, offers a similar feature).

Fighting Twitter Spam

SocialToo, of course, was responsible for quite a few of these spam messages in the early days of Twitter; though this February, SocialToo's CEO Jesse Stay announced that the service would end support for auto DMs, and SocialToo had been already offering some basic tools to fight auto-following spammers. Others have now jumped into this market, and the problem is getting more pronounced by the day. Of course, the problem of Twitter spam in general is getting worse, too, and we are still waiting for a good third-party solution to filter spam messages in our regular Twitter stream or for Twitter to put its foot down and implement better spam filters itself.

The TweetBlocker dashboard allows you to unfollow and block users individually or as a group. You can also hover over a user's avatar and see their last couple of tweets - just in case you are not quite sure if somebody is really a spammer.

Grades

Overall, TweetBlocker works just as advertised. We noticed, however, that while it did really well for those Twitter users it gave a C or D to, there were quite a few false positives among those users it graded with an F. These are supposed to be the worst of the worst spammers, but far too often they just turned out to be hapless Twitter users or people who had abandoned their accounts after a short time. 

APIs, Bookmarklets, and Integration

While the website is obviously the central focus of TweetBlocker, the company also provides an API for developers, as well as a bookmarklet that allows users to report spammers to TweetBlocker directly.

As a standalone service, TweetBlocker is already quite interesting. Things might get a lot more interesting in the near future, though. Jonathan Nelson, the product director of Hashrocket, tells us that Tweetie, the popular Twitter app, will integrate TweetBlocker with the next version of its application.

Note: Whenever you suspect that somebody is indeed a spammer, you can also send a direct message to @spam, Twitter's own spam fighting account.

Ironically, if anyone's to blame for spamming our Twitter timelines, it's the marketers themselves. They've managed to trick our friends into spamming us with their messages instead.

We're not sure where anyone, marketer or not, gets off telling Twitter that it's their responsibility to filter the content that flows through their service mainly because Twitter is already doing so. The company itself currently addresses the spam issue by providing an @spam account where you can report spammers and other abusers in the Twittersphere. If the account in question is indeed a spammer, Twitter boots them from the service. That sounds good to us. Simple and effective...at least for the end user. (It's probably a nightmare to deal with at Twitter HQ).

Of course, Twitter doesn't want their service overrun by spammers - no one would. However, they're probably more concerned with wasting their resources to support these fake accounts than they are with the annoyance it causes for their users. But do they have it under control? Perhaps not - fighting spam is sort of like fighting computer viruses. You block one and someone makes a new one. The same goes for spammers - kill one spammer and another appears to take his place. It's an ongoing fight, not a plague that can be wiped out overnight through some magic filter.

Besides, what you consider spam, I may consider "valuable information about a product." Probably not, but there is a gray area there that has to be taken into consideration. Some spam is out-and-out spam, but other stuff may just be "hot deals" from a legitimate company. However, if you didn't want to see said hot deals, you might consider them spam. Still, how would you see them unless you actually followed that account to begin with? Or maybe you turned on auto-follow using a service like SocialToo? If that's the case, it's a little ridiculous for you to get annoyed when half your timeline turns into a slew of "buy this" messages - you only have yourself to blame for that.

Where Actual Spam Hurts Us

The only place that honest-to-goodness spam can really affect you on an everyday basis is not in your own personal timeline of friends' tweets, but when viewing a trending topic's stream or when doing a keyword search. In these cases, spammers hijacking a currently popular hashtag may show up in the timeline, potentially diluting the results with irrelevant information. For this reason alone, we support Twitter's spam-fighting efforts.

Even More Dangerous? "Tweet to Win"

What's actually more concerning than spam, however, is the new trend we'll call "tweet to win." Legitimate companies have begun using Twitter to promote a message - essentially an advertisement about their business' offerings. To cajole twitizens into "spamming" their followers in this way, they're offering prizes or the chance to win prizes in return. (Full disclosure: this author did this once and still regrets it).

This situation hasn't gotten out of hand just yet, but it seems like it's only a matter of time before it does. Because really, how many of you could resist yourselves if all of a sudden a company started giving away free Macbook Pros? Oh, apparently not too many of you because you've already spammed up trending topics today with #moonfruit. What's Moonfruit? Why, it's a company that's giving away a free Macbook Pro every day for 10 days. Is this a brilliant social media promotion (as Adam Ostrow of Mashable claims) or just a new, inventive way to junk up the twitterstream with advertisements? We think it's closer to the latter.

The only consolation in this particular case is that Moonfruit doesn't care what your tweet says, so it can just be appended to any ordinary tweet. That's not usually the case - most companies provide a message for you to re-tweet.

What's frightening about this "it's not spam, it's a message from your friend" is that it's really not. My friend isn't actually telling me that Moonfruit is this great new company they have just heard about and that I really have to check out. This isn't a word-of-mouth recommendation - my friend just wants to win a new laptop. They know this, I know this, and the company knows this. And that makes the message just as spammy to me as any other in-stream tweet from an actual spammer.

So, what can be done? Well sure, I could unfollow that so-called friend, but why would I? It's not like they do this regularly and 99% of the time, I like what they have to say. But while one day that friend is tweeting to win a Macbook, another may be tweeting to win something else. Even if only a small percentage of an ever-shifting group of my friends tweeted a promotional message every day, it would be enough to junk up my timeline.

Sadly, that's one kind of spam that Twitter can't really block. And neither can I.

They've been working on a solution to cleanse the stream of Twitter spam; their new product tags and blocks computer-generated tweets with a minimal margin of false positives. BotKiller is a product of Rarefied Technologies, an open-source company that implements advanced algorithmic classification for enterprise applications.

The company claims that its "specialized lexical parsing" can find and block computer-generated content by analyzing the metadata and the conversations and relationships between post authors and the larger network.

Currently, the service is focusing on spam filtering for real-time UGC, and Twitter provides a case-study playground for the the product's accuracy and effectiveness. Overall, the company cites a 95 percent accuracy rate for spam filtering with a set of false positives equal to less than one percent of all blocked tweets.

Here, we can see a sampling of blocked tweets from a sample of about 3 million tweets:

Clearly, there are still false positives, some of which do appear to be auto-tweets about new blog posts. Rarefied CEO, Gabriel Ortiz, wrote to us in an email this afternoon, "We haven't really made a decision regarding auto-tweeted blog posts, right now we're trying to tag the ones that are from obvious spam blogs, such as those selling prescription drugs or promoting multilevel marketing scams, but we're not yet blocking ALL such blog post tweets, as some of them might be more legitimate."

According to Ortiz, the BotKiller product is currently just a proof-of-concept for their real-time spam classifier. As such, whether the service will be free for end users or how pricing would be tiered is yet to be determined. "We're hoping we can partner with someone who has a desktop or mobile Twitter client to deliver the filtering service to users," he wrote. "It would also make a lot of sense for Twitter themselves to license our solution so they could just mark as private tweets which are likely to be spam, thus keeping them out of the public search and trending topics without stopping people who wish to read messages of that nature from doing so."