A lot of the sentiment in this thread makes it clear that Social Media (Google/FB/TikTok) is a tool capable of exerting power, a weapon.
The great firewall of china prevents American "weapons" from running rampant on Chinese citizens. Meanwhile America has no digital border, so Chinese weapons are able to run rampant on us. If you ask just about anyone "Is it ok for China to store bombs in our cities, while they prevent us from putting bombs in theirs" the answer is obvious.
Despite this America has chosen a "one internet" strategy to prevent the balkanization of the internet and generally has an anti-protectionism strategy.
The far more interesting question is "despite the obvious national security risk posed by TikTok, why might it be preferable to not block it?"
I remember when the CCP was evil for bringing up this firewall and how repressed all their citizens were and how we should be happy because we live in a free and open society blah blah blah
And now firewalls are good, because apparently now apps are "national security threats", interesting.
These aren't just ideas, these are adversarial fingers on the scale, particularly in a country that has a nearly 50/50 schism. Then there are the intelligence possibilities.
There is potentially geolocation, timing information, visual information, identifier based information, text scraping based information, artifact information, and social graph information. When and where a person sleeps, commutes, works, and vacations. Who shows up in my pictures and contact list, potentially how close those relationships are. What types of devices might show up on my network. It's possible to potentially connect a TikTok account to other public accounts based on links, shares, text, or other content. I don't now what an apps ability to scrape through photos on a phone in the background is, but even a hash on every photo could be used to identify anyone who has a non public photo on their phone. Direct messages are their own treasure trove. You might be able to fingerprint the device or collect version information which might make landing a vulnerability on a particular target easier.
If I gave you the TikTok database and a function that will control what shows up in peoples feeds, I don't think it's very hard to imagine ways to create civil unrest, promote a friendly politician, identify military members, identify politicians, identify politicians children, diminish trust in public institutions, increase hopelesness/depression, drive up hatred to outgroups (people of a different gender race or sexual preference), or drive up hatred towards police.
We are living in an age where the ideas of objective truth and intellectual authority are gone. Nuance is dead. Everyone can choose their own reality. Presenting emotionally satisfying, yet ultimately destructive realities to people seems like the type of thing that can become quite problematic.
As a side note, from an ideological point of view, I am against banning TikTok, but it's hard not to see that it is the pragmatically correct thing to do. Certainly if China were to invade Taiwan, I think pragmatic concerns would exceed ideological ones.
We've had only approximately 1700 years of totalizing orthodox hegemony with the advent of heresy in late antiquity. Most of human existence hasn't been under the thumb of such world views. I'm sure we'll survive. Such a fear isn't based in a plurality of of worldviews - it's the fear of no longer being able to assert the dominant worldview.
The great firewall of china prevents American "weapons" from running rampant on Chinese citizens. Meanwhile America has no digital border, so Chinese weapons are able to run rampant on us. If you ask just about anyone "Is it ok for China to store bombs in our cities, while they prevent us from putting bombs in theirs" the answer is obvious.
Despite this America has chosen a "one internet" strategy to prevent the balkanization of the internet and generally has an anti-protectionism strategy.
The far more interesting question is "despite the obvious national security risk posed by TikTok, why might it be preferable to not block it?"