I registered romrealm.com. I'm going to start a comprehensive ROM site. Do you think that would be ok? I don't know of any ROM site that have been shut down. Coolroms.com gets 50,000 unique visitors a day so I'm sure if I developed the site well I could make a bomb from adsense.
By your logic, if someone else is doing something and not getting in trouble--yet--then it's legal and okay for you to do it. Here's a hint. When you are in court, you can't point to another person's or company's illegal behavior to excuse your own. The mere fact that you need to post in a legal area asking if your site will be okay should be an indicator to you.
Since hosting ROM is illegal, you would not be allowed to use Adsense on those sites. Do not attempt to do something illegal because there are consequences. If you still want to do it, just be prepared to be caught in the near future.
Just drop the domain, and save yourself the hassle of getting a lawyer! No seriously its really not worth trying to make a few quick bucks.