There are tangentially similar precedents already, such as the American FACTA law. It is obviously a quite different context, as it just relates to financial information, not all information - but it's a law from the US government, that demands foreign companies send information back to the US.
The wild thing is that foreign companies actually do it. To avoid annoying the US, a lot of other governments ensure that the data is reported.
The US can get away with this through its immense power and economic influence (for the moment, at least). The UK is a small market of middling relevance, and their government's belief that they're a global power is an anachronism. I hope these decisions cause enough companies to break ties that they're forced to realize their position.
The key difference being that it is perfectly legal for the US to request data on income and gains received by US taxpayers while it is illegal for the US to spy (in certain ways) on US residents.
It is completely routine for countries to exchange data on financial accounts [1]. The only aspect that makes FATCA somewhat unusual is that the US taxes US persons even when they are residents of other countries.
Oh 100%, the content (and context) is completely different. The similarity I mean is a government passing a law that asks a foreign company to hand data over to them.
It's legal in the same way this UK thing is legal - because there's a law justifying it. It may make more moral sense, depending on your political persuasion.
The wild thing is that foreign companies actually do it. To avoid annoying the US, a lot of other governments ensure that the data is reported.
https://en.wikipedia.org/wiki/Foreign_Account_Tax_Compliance...