Tell me how often malicious one person could click on my ads to get me banned, is it 1 time per minute or what? How does adsense figure out when its acceptable rate of clicking or not any clues?
Adsense doesn't give any information on how do they measure invalid clicks but for pre-caution, as soon as you see some malicious activity, report it to adsense to be on a safer side.
its like asking how many a times to get warning before it turns a crime why u want to get into it, do not make clicks to ur own ads, try control your mouse to click on to it, in case u do it by mistake report it to google.
I don't think they'd reveal that kind of info, but I assume Google stores the ip address of anyone who clicks on the ads for a specific Adsense account, so even one click a day on your own site could get you banned if you do it for a couple weeks.