lexipixel - 5:08 pm on Apr 6, 2012 (gmt 0)
Part of the problem is people who are desperate for followers, and don't consider who, (or in many cases "what" is following them).
When I get a notice that someone is following my account, I immediately check them out -- if the account is following 3,000 others or has 1000 followers -- but has only posted 120 times, it raises a flag and they get blocked. If they pass my "numbers" metrics, (e.g.- they have 1000 followers and have tweeted 3000 times), I check what it is they're tweeting about --- a lot of times it's the same tweet over and over every hour, or nothing more than automated "I'm at the dry cleaners", "I'm at the car wash" type of tweets -- again, blocked.
If they don't already, I hope twitter takes into account how many people have blocked a "twit" -- and maybe use it as a metric for shutting down the account.
Another part of the equation is alerting the email providers, (gmail, hotmail, yahoo especially), when email used to signup for a twitter account is used.
I still keep wondering why AKISMET type spam filtering isn't deployed to more platforms. WordPress (Automatic) does a great job of filtering 99% of the crap -- they do it by casting a wide net --- spammers rely on volume -- when AKISMET sees the same blog post, the same email account, the same IP, etc.. posting to hundreds or thousands of blogs, (especially the usual comments like: "I much appreciate how you write about this subject, I will visit this blog often")... it trips the filter and the millions of possible targets never see the comment spam or have to spend time cleaning up the mess.