A viral TikTok account is doxing ordinary and otherwise anonymous people on the internet using off-the-shelf facial recognition technology, creating content and growing a following by taking advantage of a fundamental new truth: privacy is now essentially dead in public spaces.
I haven't read much about the doxxing this account does, but that side seems more clear cut
The harassment though is much harder to go after, and maybe harassment is not the right word for it. You could do something very innocuous, like eating your sandwich a little weird or not having a perfect reaction to a random tiktok influencer coming up to 'interview' you, and now there are millions of people commenting about you and making memes of you. I don't see what you could do other than convince Tiktok to take the video down, and even then the damage is already done.