This may be common knowledge by now, but I just found out the hard way that CrowdSource is putting CAPTCHA in their HIT's to identify people who are using scripts, and they are banning these workers. FYI
As in unattended scripts to do their hits while you're not there? It's not too hard to see the little box to click to say you're not a robot
You should be grateful that only CrowdSource has banned you and not AMT themselves. ref: https://www.mturk.com/mturk/conditionsofuse , section 3b. Kindly note the key phrase “to complete the Services”
Related, I was hamming a hit hosted on aws servers yesterday and every 100 or so submissions I got this weird popup that blocks access to the hit frame (dismissible with a click or enter)... ...I think it's possible that Amazon themselves are following cs' lead (or vice versa)