harassment based on the idea of 'slutshaming' or any other type of malicious rumours

I am just curious as to why so many people in Irish society think harassing someone to the verge of suicide is OK, if someone has spread malicious lies about them? When I say harassing, I don't mean confronting them and talking to them, I mean making loud comments in their hearing and generally making them fearful of leaving the house etc... It's crystal clear that this type of harassment is absolutely acceptable in Ireland. I am curious as to why. I wonder why, firstly, someone would consider it fine to bully someone based on something that they haven't even witnessed evidence of, and secondly, why they consider the victim's life to be worth less than their own. I welcome any thoughts.