While anyone is vulnerable to harassment online (and offline as well), some people and groups are much more prone to harassment, particularly marginalized and oppressed people in a society. Historically of course, different demographic groups have been subject to harassment or violence, such as women, LGBTA+ people, and Black people (e.g., the FBI trying to convince Martin Luther King Jr. to commit suicide). On social media this is true as well. For example, the last section mentioned the (partially bot-driven) harassment campaign against Meghan Markle and Prince Henry was at least partially driven by Meghan Markle being Black (the same racism shown in the British Press).
I find that women seem to be more vulnerable to attack than men. Take what happened recently as an example. Recently, an amateur named Mai Mai participated in a divorce variety show. Her performance in the show received a lot of attacks due to her excessive individualism. Almost every video related to her received a lot of criticism from netizens (almost 10,000 comments), and she was also on the hot search many times because of her performance. But on the other hand, a male rapper did a lot of unethical things, insulting fans, sleeping with fans, etc. Although the severity of these behaviors was far greater than that of the previous woman, his discussion was far less than that of the previous lady, even though he was an artist.