This is simply not true. Police may not keep you detained if they do not have probable cause or reasonable suspicion that you have committed a crime. However, in real life, they do this sometimes, even though it's been ruled unconstitutional.
They do occasionally face repercussions. Thousands of civil rights lawsuits are settled quietly around the country every year, and some go to court and establish precedents, such as Turner v. Driver.
They don't suffer consequences enough, though, and depend on citizens not knowing that what the police are doing is wrong. It's also difficult due to the "thin blue line" BS where cops are elevated above the rest of society.
They don't have to charge you, so they don't have to prove it.
> They don't suffer consequences enough, though, and depend on citizens not knowing that what the police are doing is wrong. It's also difficult due to the "thin blue line" BS where cops are elevated above the rest of society.
The police themselves hardly ever face consequences; the settlements come from the taxpayer.
They have to have PC to arrest someone. Even if you're not charged, PC has to be there for an arrest to be justified.
I believe this is called a distinction without difference. The police can always say you behaved suspiciously or they felt threatened by you. You can also be found guilty of resisting arrest, even if there was no reason for the arrest except that you were resisting it.