It's not really helpful to keep alluding to a specific situation, guys, as nobody knows the full details and could well be jumping to conclusions, so let's just stick to general advice. :wave:
Not talking about the OP's situation specifically but there are things people can do if they're worried about somebody's online behaviour - cyberstalking can be reported to the police for example - but I don't think it's actually an offence to just be able to read what somebody else has written; you actually need to be harassing them in one way or another too.
If that isn't the case, then it boils down to what's already been said - people need to think about what info they're posting and whether that could possibly be used against them in some way....... and that's good practice in general, I think.