It would require more than 30secs thought but I'm sure there are some heuristics which will work. I'm not even convinced the "report spam" button is connected to any action on twitter's server. And why not use blocking as an indicator? Surely if Person A @-replies several people, and they block A, then just disable @-replies from A.

Has anyone tried using a Bayesian filter for twitter spam? These have been very successful for email. In fact, I consider email spam a solved problem now (thanks Gmail!)

It's for things like this that I wish I could insert a proxy between my twitter clients and twitter itself and build my own rules/spam filter.

Sounds like you would prefer a communications medium not running a proprietary protocol controlled by a single company whose business model relies on their ability flake sure you cannot block unwanted content.

I cannot think of a single non-spam case where somebody would @-tweet the same link to a hundred people. That won't capture all spam, but it's a pretty easy low-pass filter.

True. @-tweeting the same message is indeed low hanging fruit. But spam gets sophisticated as the arms race continues.

My assertion is that after a certain point (which we are not far from), Twitter as a platform will have a problem making a distinction between "spam" and "legitimate content".

I think there's definitely potential for an arms-race here (just like there was with email spam) but I don't think it's a reason for twitter to not enter the battle at all.

Also, the @-tweeting is easy to ignore. Yes, you have to check who is replying to you a few more times than you would have, but it's not the end of Twitter.

Where you can see the real problem is when there are trending hashtags that spammers get a hold of... spammers grab hold onto a hashtag and keep it artifically trending long past its relevance.