I am not a developer but i have two suggestion which help Q2A users to prevent their adsense account from invalid acitivity. If anyone can develop these plugins then it would be a great help to community
1. Adsense click fraud : In this plugin if any bot or user click on adsense more then 2 times the adsense will be hide for 12 hours and another optional banner will be displayed in place of adsense.
2. Adsense Hide for NSFW categories/questions/tags etc: In this plugin option available to hide adsense from NSFW contents and show alternate banners.