That screenshot was really high on the "weird dude power fantasy" scale. I find it very hard to believe that a cop could waste that much effort trying to burn a single prostitute.
Being a cop is a job, and at your job your boss is on your case about productivity and numbers. "I'm setting up a fake john in a different state to try to snare a single lady for prostitution" just does not move the needle enough to justify the effort
But as a "I hate whores and dream I was a cop with the power to mess with them" fantasy that screenshot works really well
It's not a "a job". As an institution police spend a lot of effort and resources to make sure that the stuff they do is perceived as a kind of calling and very special, which is important to foster loyalty between cops and helps them psychologically endure exposing vulnerable people to violence and incapacitation.
Legally they're in a protected category and 'above the law' in many ways. They get to break into other people's homes, dig through their stuff, spy on and hurt them. Commonly they're told that these actions are what keeps society from hurtling into barbarism.
Being told you are superior to others is not psychologically innocent.
That forum post was made by George Erdel of the Beaufort Police Department, an actual cop.