What I have found is that most forums are open to scrutiny by their very nature of information sharing; that you don’t have to be a member, or be in a forum site as a guest to find information that may be detrimental to your privacy. I can therefore understand the reticence of administrators to allow complete freedom for all posts.
Just look at a post you have written in HHAD, pick out three unique nouns such as places and people, put them in Google search and Bingo! There is a good chance only a few searches need to be looked at and one will be a HHAD post or what ever forum you belong to. I have tried that on my own posts to confirm this. (No, I didn't google my own name).

In a non-Thai small forum I used to belong to, some time ago I posted information about a dalliance in Bangkok and mentioning a small bar by name. A year later I googled ‘Bangkok’ and the bar name in trying to remember the exact address, then up popped that particular forum post and details. I thought this info was private. I was gobsmacked. I had been run over by a search engine and it had left skid marks. I felt foolish at my naivety.

Thus I am circumspect with some information I put in posts. A good researcher does not need your name to quickly build up a profile on a member and identify them.
However, the ‘Night Crawlers’ sub forum is isolated from Google searching and bots which would be a relief to many.