The flaw, which Twitter said Monday it has fixed, allowed users to add anyone else as a follower of their tweets. Normally, the other person has to initiate such "following."
It's unclear how long the flaw existed and how many people took advantage of it. Twitter Inc. says it's looking at the issue.
A side effect of the fix was that for about an hour on Monday, Twitter users showed zero followers while the company fixed the problem.
People who exploited the bug got more than an ego boost from having famous people appear to be their fans. For a time, those celebrities really did become their audience and received the tweets from people who had fraudulently added them as followers.
Twitter recommends that users who were fraudulently added as a follower to someone else's account should click "unfollow" to take themselves off those lists.
The company emphasized that updates on accounts set with privacy restrictions weren't made public because of the bug. Information on such "protected" accounts is hidden from public view, unless the account owner approves specific people to view updates.
