Twitter announced it has filed suit in federal court in San Francisco against five companies it says are behind much of the spam that appears on Twitter—that is, companies that build tools designed to distribute spam on Twitter, as well as the web.

“With this suit, we’re going straight to the source,” Twitter said in a blog post announcing the suits.

The Ever-growing Problem of Spam

Without a doubt, spam in the email inbox and many web outlets, is wearing on consumers’ patience and businesses’ wallets.   Small businesses, in particular, feel the brunt, with 52% of such companies claiming that the volume of spam their organization receives has increased over the past year, compared to just 16% who say that it has decreased, according to survey results released in March 2012 by GFI Software.

Twitter Users Say Only 36% of Tweets Worth Reading

Spam is a particular problem for Twitter, though, as one study suggests the site already has a challenge in getting users to take its messages seriously.

Twitter users rated only 36% of the tweets they received as worth reading, while they expressed ambivalence about 39% and said 25% were not worth reading, according to research released in January 2012 by Carnegie Mellon University (CMU), which looked at data gleaned from December 2010 to January 2011.

Boring Tweets Most to Blame

Data from “Who Gives a Tweet” found that being boring was a prevalent problem on Twitter, as this reason accounted for 82% of all explanations for followers rating a tweet not worth reading.