From the Blog Post:
"Maybe you've noticed, for the last few days some google ads appeared on this blog, but they have disappeared now again. That's because I just got banned from google adsense for life time (as it seems), although I didn't do anything wrong."
Not only that, but they are witholding monies already earned by his ads prior to the accusation.
"In that mail, they did not even tell me any information about their problem with my ads, only "invalid clicks or page impressions". No IP adresses, no channel ID, no website, no time or date, no amount of clicks, nothing. No way for me to find out what was wrong. There was the possibility to contradict, and I tried to explain some possible causes like the sudden increased amount of traffic, but they ignored me. The interesting thing: They now even won't pay out the money I already earned before the occurance of their 'invalid clicks' assert. "
Check out the full story HERE