Because you are allowing company B to technically enter your home. But for them to do that wouldn’t Company A need a warrant for using Company B to enter your home? The same way as far as I know get a warrant to search pedo’s devices and entering home. I definitely know they need to have a warrant to tap your phone and stuff.
That is not how internet piracy is handled.
Rightholders are so lazy they send the ISP an email that reads like my first legal letter referencing laws that don’t exist in your country expecting you to do something.
We laughed each time one came in and deleted most of them. The only ones we forwarded on to actual customers was to schools because they can use the info on the notice to plug their student security appliances.
Back to the original point, if you wanted to try something like getting a court order, you would need to show you have standing to begin the case.