I run a network for community forums. My forums have been spammed a few times with objectionable content.
When this happens, usually I get warning from adsense asking me to remove the objectionable content with in 48 hours. Sometimes, they block adsense on my website and email me about it. I promptly removed the content and reverted back. Adsense was restored on my website after a few days.
This has been going on with my forums for many years. Mostly users spamming objectionable content, but sometimes I get slapped for having ads on login/404 ("contentless") pages and other rule violations.
I get disabled, Google lets me know, I fix the issue, appeal, and get Adsense restored. My forums have Adsense incomes that range from $100/mo to $1800/mo.
Google has been great so far. It does feel precarious to have all my eggs in the Adsense basket, but the payout from other ad networks is abysmal in comparison.
When this happens, usually I get warning from adsense asking me to remove the objectionable content with in 48 hours. Sometimes, they block adsense on my website and email me about it. I promptly removed the content and reverted back. Adsense was restored on my website after a few days.