The bug appears to be an SMS command that's normally used to accept a follow request but when tweeted forces a user to follow your account. We asked Twitter if it was aware of the bug and Twitter spokesperson Sean Garrett said, "We are aware and the team is on it."

The bug could be embarrassing for some who might suddenly follow some interesting spam accounts or racy Twitter accounts. In the meantime, though, it looks like Oprah and friends are on a serious Twitter-following binge this morning.

What remains to be seen is how Twitter will handle this. Will users be responsible for unfollowing all of these new follows or will Twitter be able to do that for them?

When we first looked at this bug not more than a half hour ago, Bill Gates was following 155 people. Now, he's quickly rocketed up to 411 and it's quickly climbing. Will it be his responsibility to unfollow all of us?

Update: Twitter has updated its blog to say the following about the situation:

We identified and resolved a bug that permitted a user to "force" other users to follow them. We're now working to rollback all abuse of the bug that took place. Follower/following numbers are currently at 0; we're aware and this too should shortly be resolved.

Update (10:18 AM PST): Of note: protected updates did not become public as a result of this bug.