system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If police officers are not required to tell us when they are undercover, what stops all police offers from just wearing normal clothes and always being undercover?

I don't see why police officers wouldn't just always stay undercover so that people didn't know they were there. I know this would be a bad thing for then to be able to do, but I don't know why they can't do it.
gpt
Why would they?

Clearly marked police presence is a crime deterrent. Very few police activities involve being sneaky and doing undercover stuff (though that's what you see on TV and the movies). A lot of what police do, like helping people, really isn't possible if you don't know who they are.