What's going on with TikTok getting banned?

My personal pet theory is the US alphabet boys have a deal with all the other social media giants for first pick of data they mine, and TikTok didn't want to play ball.

The NSA had a plan to implement a wide spectrum data capture on US citizens ... which it cancelled right around the same time Facebook got a large angel investment.

https://unlimitedhangout.com/2021/04/investigative-reports/the-military-origins-of-facebook/

You are nearly certainly correct that TikTok did not want play the same game as other US social media.

While data privacy is a concern, in my opinion the real fear motivating the government is the massive control China has, indirectly, through TikTok, over citizens' beliefs and culture.

As another comment pointed out, Facebook (and Cambridge Analytica) had an enormous role in Donald Trump getting elected. That is the kind of influence and power that shouldn't be in the hands of a foreign power (ironically, it's the kind of power the US has wielded for generations over many countries). And the US especially doesn't want China or Russia to have that power.

If China felt inclined, they very likely could push to have the algorithm modified to fit a particular agenda - say perhaps promoting a pro-China candidate - and most users would barely notice and slowly be drip fed posts that nudge them in a particular direction. People in power could start to lose that power at the behest of TikTok.

As many will likely point out, there's a good arm's distance between China and TikTok right now, as far as we know, but it's possible they are more involved than they let on (much like the NSA and Facebook) and could become more involved over time. It's a risk the government is unwilling to take.

A good example of what kinds of things can happen is when TikTok published a post to every US user with their congressperson's number, urging them to call them to protest the ban. I'm certain that scared the shit out of the US government and probably did more to force the ban down mid than anything else.

IMHO you're kinda right. There's a trade war going on between the US and China, and data is damn valuable so it's just logical to prevent the enemy access to your own citizens' data, specially since we know how it's used to manipulate elections (Russia's been proven guilty of it for the 2016 US elections), but also Facebook was at least paid to do so.
Now I do agree with you in that the ban is probably due to the wrong reasons though. But it kinda doesn't matter to me.

Yet I am not US citizen either, I'm an EU citizen, so my opinion on US politics ain't quite relevant. I just wished we would do the same here in Europe and more consequently. Both the US and China do have laws that require companies to hand over there user data to their respective country's agencies, which is technically illegal under GDPR for EU citizens' data (they shouldn't be able to leave the EU). So we should ban all social media that stores data on servers belonging to US or Chinese companies (leaving basically only fediverse instances on european servers).

Caymans LA Singapore. Singapore.

A few years ago, all of that was China and nothing else but China.

Maybe these "international" items are just deliberate actions to conceil the truth?

ByteDance is registered in the Caymans, with global headquarters in LA and Singapore

Literally the first sentence of ByteDance's wikipedia article says they're HQed in Beijing. Which means the CCP has unfettered access to the company's property and can strong-arm their leadership to do their bidding (as is standard for all Chinese businesses).

The data TikTok collects is extremely sensitive and is digital gold for things like training facial recognition models, which China totally does not use for bad things

But nice try, comrade bot