Check out the Urban Legend site:

I read that there used to be a practice, especially at massage parlors, where the client, without saying a word or offering money, had to drop down and lick the provider to prove he wasn't a cop.  Then they could talk business.

There are some states (maybe FL?) where LE can actually have sex and then arrest the woman!

Was one instance in Phoenix, that I saw reported on cable news where they arrested them after having sex.  Most debating the topic figured it would be thrown out because the cops engaged in the "crime," but the top cop or prosecutor (I forget which) was doing all the news talk programs defending it as a legitimate way to lick prostitution...'scuse the pun.  Probably could google it and find the report on Phoenix..was fairly recent.  Near election time as I recall, as if others didn't already guess that small fact.  

http://www.sexwork.com/Phoenix/SheriffJoebustbusted.html

That's the dude...thanks SC!

BTW, I wonder if a relative of his is in LE in St. Paul LOL

I am a South Floridian and in FL they don't have sex then arrest them. In fact I have seen a bust happen and not only did they not want to touch the girls, they put on gloves before arresting her. These were upscale girls who charges hundreds of dollars an hour, had perfectly coifed hair and a 10+ appearance and they were treated like $2 street whores. LE doesn't think highly of providers in FL. To them we are all diseased and infested with lice. That's how we are treated. I have heard the talk of a few girls busted and they all have had the same experience.