Is telling other you suspect someone in a police informer obstruction?

Here is the scenario I’ve heard where someone claims they were charged with obstruction. To head off the cite requests it isn’t a news story. Lets say USA to keep it simple.

A mutual group of friends who hang out get joined by a new guy, new guy approaches several group members individually and asks if they can hook him up with hard drugs in a very odd blatant manner. They realize from talking to each other that he has approached more than one of them, so they email all their friends telling them what the new guy is doing and to stay away from the creep because he could be a police informant. The one who sent the email is then charged with obstruction of justice or something similar.

Is it plausible the charge would stick?

I don’t see how this could be obstruction. Maybe you have one rather overzealous police and prosecution service. Or more likely one of the posters was privy and revealed. The latter I can see as obstruction.

Fun fact. When I lived in London, the rule of the thumb for street hookers was. Avoid, most are ugly/ diseased and the better looking ones are cops.

Sounds like a bit of a stretch to me. In general, obstruction of justice involves either lying to investigators, or concealing or destroying evidence. “Outing” a police informant seems to fall well short of this.

I don’t see how that could possibly be breaking the law. Right off the bat, it’s not like anyone actually knows anything.

The way I usually see this scenario play out is that you see a speed trap, pass it, then flash your lights at on coming traffic to warn them of the officer clocking traffic. The cop then pulls over the person flashing their brights and gives them a ticket for obstructing justice. Or at least that’s the story, I’m not sure if it ever actually happens.

If cops could arrest people for NOT selling drugs AND for selling drugs, that would make their job a lot easier. “Hey man, can I buy some cocaine” “NO!? Well, you’re under arrest for obstructing justice, you can’t not sell it to me just because you think I’m a cop”.

ISTM I’ve seen that story from time to time over the years, and ISTM (vaguely recalling) that such a charge doesn’t stick. Anyone know any differently?

I think, further, that I read of at least one case where the story made a minor stink in the local headlines, with the conclusion that the police agreed not to do that any more. (Try to nail people for warning others of speed traps, that is.)

It has in the UK: http://www.dailymail.co.uk/news/article-2157763/Drivers-fined-flashing-headlights-warn-oncoming-cars-police-speed-trap.html