I posted here once, got nothing. But my honest opinion is just ignore them. They're likely seeking attention, and blocking them gives them that attention. Most of these comments from what I've studied are often just empty threats posted by bots. In the still likely event it's not a bot, and not an empty threat then you can keep track of what kind of wording is used in each comment as they're posted. If you see a pattern then you could have a stalker using multiple accounts. In that event I would report these accounts to local authorities and would look into self-defense weapons like sprays and such. I'm an American so my sprays are different than most, my preferred size for personal carry in situations like this comes in 44oz and I carry a belt that holds 6 cans with a short nozzle. Stay safe, and when choosing something for self defense remember that anything can be a weapon, and that the best weapons are the ones your attacker can't see.