If we're talking about national governments as authorities, there are about 200 different authorities on the planet. And none of them knows who owns the Bitcoin address you're sending to, so none of them can know which exchanger received your funds, so none of them can ask that exchanger within seconds to freeze your funds. This power is entirely concentrated with companies that sell the notion of taint, and none of them are transparent about their criteria.
The thing is, there's no direct "request" from the authorities, but the exchanges are looking out for themselves. They have to be in the good books of the authorities because if they don't, they could be shut down, and even if they are not shut down, in their POV, it is better to be on the good side of the government than on the bad side.
For they to be on the good side of the authorities and also have their customers trust them, they have to provide a thousand-page "terms of service" and do the exact opposite when it suits them.
It's the same with how the authorities have the banks and other financial organisations by the throat in my country. They have to compromise or face numerous ridiculous issues that will make business difficult for them. It got to a point where I began to see systemic social media campaigns by influencers against a financial institution that refused to yield, till they finally did.
So right now, those institutions don't need a direct request from the authorities before they do what the authorities would want.
