First you need to know, I am not picking on Twitter - nor am I singling them out. If you have distribution - email,IM,Social Network - ANYWHERE there is a mass audience you can be certain the spammers will get there. Now I have been threatening to do a post on how Twitter is all about the "Soft Sell" , and this STILL is not that. But this is how they will spam you, and why it is a threat to Twitter.
As an experiment, to prove a point - I threw out a bunch of random Tweets, with Keywords that I thought might be bait for opportunists.
[NOTE I had intended to upload a Photo to post HERE showing my random Tweets - but got a message from Google that I had exceeded my limit