My understanding is that there are quite a few perceived threats, but all of them apply to large US corporations as well. If you collect enough information on

My understanding is that there are quite a few perceived threats, but all of them apply to large US corporations as well. If you collect enough information on people, they can be manipulated to certain beliefs or actions. This is the same information that Facebook and Google use for advertising purposes, similar information to the Cambridge Analytica events, and the risk is China (or a nefarious actor with this information) using it to "meddle" within the US. Apps collecting sensitive information (which maybe TikTok content counts as?) can also be used for blackmail, especially when owned by a foreign government which wouldn't even blink at blackmail. There are other more paranoia-centered concerns around essentially-real-time location data being used to "know where in the country to attack". Basically there are definitely legitimate concerns around large-scale data collection, but the "National Security" concern definitely seems to be "China is less trustworthy than any American company". This is just my understanding, and am open to being proven wrong here. Update: I forgot to mention that I do believe there is a legitimate concern around a foreign government having what is effectively editorial control over a platform which is used by a rather-easily-influenced group as a "news source". Whether or not social media should ever be considered a source of news is a different discussion, but if a large section of the US population is believing what they see on TikTok as fact, and the content on TikTok is editorialized by a foreign state actor, it is a legitimate concern.