TikTok is one of the worst privacy invasions in existence (a few selected links at the bottom, but you can find thousands more with a simple web search). So much so, that the FCC is recommend that the app is banned in the US.
This particular app is a fucking abomination, and makes Facebook's privacy invasion look like angels by comparison (at least FB openly admits it!).
Reflecting on it, it's quite sad how it has captured most of the young generation and making them dumb. There are a few tough bunches who resisted subjugation (such as quite proudly myself), but it's grasp is near total, that I even read somewhere that the US. Army is using it for promotion.