I think you need script to banned ip country.. Just example you not want country A display or see your adsense ads so automaticly all vistor come from country A will not display adsense and it required ip database but I will post it here if you need
I'd probably start with this script, and keep adding ip addresses as they appear. At least that way you have evidence of trying to prevent it while you figure out what to do. Evidence may mean the difference between google banning you or not.
I wouldn't worry about it. I think Google is well aware that sometime people do this when they are visiting a website. I've found, however, that Google often doesn't count more than one click if they are done in quick succession. If worried, you can email Google about what they suggest in these cases (not after each time it happens). Click bombing, as I understand it, is the same IP clicking ads 10, 20 times or more. THAT I report, but 2-4 times, nah. It's just how it is sometimes.
I use statcounter on my websites, and can see the IP of visitors by clicking "recent visitor activity." I assume many other analytics type programs gives you the same data.