OSDev.org

The topic of COPPA came up last Fall, and... well, it wasn't pretty. I take the blame for that, as I was one of the ones to bring it up. Long story short, there was a poster who was claiming to be 9 (it seems likely that he wasn't) and was notable for his rather unpleasant behavior, and another who wasn't so bad but apparently actually was 11, and there was vigorous debate over whether they should be banned, either temporarily or permanently, due to this. Accusations were being made that it was only brought up in order to push out said help vampire (I had somewhat mockingly mentioned it regarding his claim to be underage in the hope he would be more forthright, unaware that there actually was at least one under-13 member around, and it blew up in my face).

As for other data protection laws in the US, to the best of my knowledge they tend to focus on Personally Identifying Information with regards to medical and legal records; save for COPPA, which is mainly applies parental control of access to websites where money might be changing hands, I know of no laws in the US that apply to data rights of any kind with regards to public fora, online or otherwise. The laws which come closest are those regarding doxxing, and that is treated mainly in terms of harassment and stalking - all of those laws, AFAIK, would require a court order to be applied.

I expect that there is a lot that I don't know, however, so I will defer to others who are more familiar with the applicable laws, if any.

I think the site should allow deleting accounts. If wanted, the owners could just keep the threads, posts, etc. but delete the persons account. Something to be nice...

There is no good way to do it. Looking at StackOverflow, which allows to remove an account (replacing the username with user<number>), you still have the reactions of other users, referring to a user name that isn't present in the thread anymore. That's...

1) confusing to read, and

2) still allows connecting the "old" user name to the "new" numerical ID, i.e. you can still link username to posts.

Any user is free to remove any personal information from his / her profile. The rest... well, choose your words carefully, as the 'net is not anonymous.