I have email and applied invalid click activity also but they cant explain. Only write ur a/c is disabled to make quality to advertisers.
I love how nobody touched the comment: "If I pay for traffic and send it to my competition, will they get banned?" I wonder if anyone has experimented with this. I think Google would be forced to ban and leave it to the person who gets banned to prove the traffic wasn't his doing (impossible).
without reason they does not disable account for sure you have not followed there rules i think so... hope so now u know there rules after this ...
Good question. I've wondered about it too. Adsense is so fragile. Big money can just disappear like that. But I think Google checks your history too, and they will probably believe the publisher's explanation. Good conduct spanning years + good earnings = Less account vulnerability.