I agree, it is really important to keep in mind how anything you write can come back to haunt you one day, even if it remains anonymous. People's online personas are part of their identity and if you get criticized for a post you made on another website with no chance even to reply... well you are just being used for their purposes.

If it gets attached to you personally then it can be orders of magnitude
worseo, for instance if anything were to be used in a legal proceeding. There's a good chance it would all be taken out of context too.

I think also of those online diary sites where people are more likely to write down specifics of their life than here.