I’ll just give you an example even if it’s not reated to unlocking phones: A black BMW 335i is filmed hitting a pedestrian and the plate number finishes with a 5. We’re gonna need to have a look at every BMW within these parameters. If you prevent the police from checking your car by hiding it, a guilty guy might have more time to hide his car and a crime is gonna go unpunished, leaving a victim with no one to pay for his injuries.

And if my car was in an unrelated accident but just happened to fit those criteria, you could use that as evidence against me (and not only that, but then stop trying to solve the crime because you've assumed the perpetrator.) It ALWAYS goes both ways. If the only way you can solve a crime is by violating people's privacy without a warrant, maybe don't be a cop.

Cops are seen as bad guys because people like you argue for why rights shouldn't apply to people, and making you get a warrant (aka doing your job) is seen as interfering with a crime.

The worst part is, it is stupidly easy to get warrants here in the US, but the cops WILL make your life miserable if you make them get one.