

Really depends on the skin color of the person visiting and where they are visiting in that country. A non-white visiting most West-European cities will be mostly fine, but if they go out to the country-side, things can be very different.
I watched a documentary of an Indian boy adopted to a Swiss family who then went back to India to visit. He had a terrible time in Switzerland due to racism and nearly as an awful time in India, because he couldn’t speak the language and people thus assumed he was a Pakistani spy.
I guess we disagree, but I’m not going to stop people from voicing their opinions and linking them to their official identities.
The problem with the internet is that it doesn’t always forget. That’s exactly why I do my best to keep my accounts separate. However, yes, semantic analysis could demask me in the future, who knows. At least it’ll give me the opportunity to say “that’s not my account”. If something is officially linked to my account, my “genius” thoughts will be bound to me and could easily be found by friends, foes, employers, whatever.
What I’m getting at is: privacy is important. Giving it up should be carefully considered, not simply done by default or thoughtlessly or “because everyone does it”.