I am not sure but I think they got that on dotalicious (apm= actions per minute). If you dont click (are active) you get auto kicked and ban.
It wouldnt take care of 100% of the cases but I think it would solve at least 85% of them... or at least would force them to click non stop and annoy hell out of them.
If it is not too hard to to apm based autokick would be nice.