Twitter, one of the most popular microblogging services just announced that they are limiting the number of followers users can have, as a way to combat spam on their service.
The way follow spam works is that a spammer joins and then quickly follows everyone s/he can find- with the idea being that the more people they follow, at least some of these people will follow back. And, of course, if they get enough people to follow back, then their updates appear in their followers timelines.
The Twitter blog refers to enacting some kind of ratio of followers to following. Their blog post did not specify exactly what the ratio is, but did mention that it is somehow related to how many people you follow, how many follow you, and, possibly, how often you tweet.
For most of us, the following limits won’t change our use of Twitter all that much. It will be interesting though to see how it impacts some of the top Tweeters, some of whom have 5,000 followers or more.