I also don't totally understand, what's a TIN for example (Taxpayer Identification Number?) and why is it making money? (Don't taxes go to the state?)

Yeah, it’s the identifier the government uses to attribute income for, and hence calculate the resulting taxes.

In this case it sounds like a midsize business is using some random guy’s number, so the tax authorities are under the impression there’s a guy pulling in millions personally, and a company with no income. Given that individuals and companies get taxed differently in many different jurisdictions concurrently this will be a mess to untangle.

Wow that's amazing, thanks for explaining