The word you want is "impunity" not "anonymity". Because awful behaviour persists in actively de-anonymized contexts (eg: Facebook) when there's a power imbalan

The word you want is "impunity" not "anonymity". Because awful behaviour persists in actively de-anonymized contexts (eg: Facebook) when there's a power imbalance that puts society (or a local subset of it) on the side of the troll and against the victim.