Have you ever had your Google AdSense account flagged for invalid clicks? It could happen to anyone, so you will have to monitor your account and be careful about malicious attempts to get your account banned. The AdSense Invalid Click Protector plugin might help. It helps reduce invalid clicks and stops click bombings.
You get to set max click limit for your ads. If a visitors exceeds the ad click threshold, they can be blocked. Those of you who have problem dealing with traffic from certain countries can simply ban them from seeing your ads. AdSense Invalid Click Protector also lets you search and review banned IPs and delete them in bulk.
As always, you will always have to be careful not to click on your own ads. Monitoring your account on a daily basis to catch issues before they become something more serious is also smart. This plugin might save your account if you are a victim of click bombing.