Twitter moves to combat 'follow spam'

In a move to combat so-called 'follow spam', Twitter has begun limiting the number of people any one user can follow.

Though the specifics of Twitter's anti-spam algorithm hasn't been published in order to make life harder for spammers, the upper limit for non-power users is thought to be 2,000. After which most users will receive the error message: "You are unable to follow more people. Please read about our following limits."

Although the Twittevangelists only became up in arms over the last day or so, Twitter co-founder Evan Williams explained the company's thinking in a blog post published last Thursday. Williams explains that the measures were a "work in progress" but that "they've already had a very positive effect in reducing (though not eliminating) the most common type of Twitter abuse: 'Follow spam.'

Follow spam is the act of following mass numbers of people, not because you're actually interested in their tweets, but simply to gain attention... In extreme cases, these automated accounts have followed so many people they've threatened the performance of the entire system. In less-extreme cases, they simply annoy thousands of legitimate users who get an email about this new follower only to find out their interest may not be entirely...sincere.

Williams concedes that there are exceptions to the rule (I'm looking at you Scoble):

On rare occasions we may see a person who is mass following and actually cares about every tweet—there is an opportunity for us to learn more about this use case and work to provide a better experience.

"There is no perfect formula", writes Williams. Although for him less is more.  "I 'only' follow about 700 accounts—less than 5% of the 16,000 who follow me", he says.

 Note: You can follow me on Twitter here.