Nope, a ban is permanent so I have not seen a single case where that was caused by a competitor I know of one case where there was a short suspension followed by a re-instatement. If you aren't up to no good, no need to worry about it
no i'm just worried about people attacking me... i'm not a theif and i'm a good person.. but bad things happen to good people if you know what that means..
If God/Allah/Shiva/Stay-Puft Marshmallow Man/etc has decided to make sure your AdSense account gets banned, there is nothing we can do to help you Sorry
Indeed, all you can do is be proactive with respect to click fraud. Your questions in general are pretty basic, though, a lot of them are answered in detail by the AdSense help page. Take the time to read through all the questions, they'll help a lot.
Guys.. thank you. all your explanation make me become more clearer. Lara, thank you for asking this question..