Cops confiscate devices all the time without good reason lmao. It’s commonplace to seize devices on a person upon arrest. Judges also grant search warrants upon very little evidence too. Cops absolutely don’t need to “prove” anything to a judge to get a warrant; there is no standard of proof at all; it’s a standard of evidence, which is not the same thing as proof, and a low standard of evidence at that.
It’s a relatively new thing. i was watching YT for years with Mullvad with no issues then late last year started getting blocked. Right now I can only watch on either NewPipe or on the official web client while logged in.