Browsing across different bitcoin related websites I rarely see any adsense ads even though lots of website do show ads.

I was wondering what the reason for this is. Does Google prohibit using adsense on bitcoin related websites? I found this topic discussing some suspicions in that direction (https://bitcointalk.org/index.php?topic=24384.0) but am wondering what the current state of affairs is.

Anybody an idea why adsense isn't often used on bitcoin websites? (or maybe my observation is wrong and someone can show me some examples of sites that do carry adsense).

p.s. I am not sure this subforum is the right section for my question, but since people making websites and project hang out here I thought I'd post it here.