Technology

It's more than just what you do in the app though. Check out some of the data any random website can find out about you here: privacy.net/analyzer/
Expand that into an app, given lots of permissions, that is tied to your phone number and email account. Given enough time and logging, it knows where you live and work, when you commute and sleep, every WiFi or mobile network you connect to and where they are located. This metadata is linked to your account and in-app activity. They have this data for you, your friends, colleagues, that weird guy you see on the bus every day... Right now, the app just uses all this to influence "your algorithm" (side note: this is also why people think some apps are actively 'listening' to conversations). But imagine a case where the govt owner of the app wants to start pushing a specific narrative, gradually swaying opinions or sowing the seeds of discourse, reinforcing it with the artificial echo chamber that is your new algorithm. /TedTalk

They are stealing data that can be (and is, often) used to track you across the entire internet. many social media platforms (again, especially tiktok) use this data to straight up manipulate people into spending more time on their platform and having views that align with the interests of the company. this is especially bad if the interests of the company are really the interests of an authoritarian government that is blatantly hostile to other countries unprovoked.