The authorities apparently got tired of asking and just went in themselves.
Canada-based Windscribe, a VPN provider, just said that one of its European servers has been allegedly seized by Dutch authorities without a warrant. According to the company’s post on X, law enforcement said that they will return it to the service provider after they “fully analyze it.” It’s unclear why law enforcement impounded just a single rack from Windscribe’s cabinet, but the VPN provider said that it only uses RAM disk servers, meaning anyone who would look through the installed SSDs would only find a stock Ubuntu install on it, so the servers shouldn’t hold any trackable data.



https://en.wikipedia.org/wiki/Parallel_construction
It’s not a law but a practice that cops do in order to use dubiously acquired evidence to build a case against someone.
Yes but that doesn’t answer the question of whether it’s an accepted practice in the EU. I’m also not so sure it isn’t somehow codified into law, in the US there’s precedents supporting it but IDK about other countries.