Sadly, this is not uncommon.
A friend told me about a different friend of his whose job was, in short, espionage for a large clothing retailer we've all heard of. I won't Fall Into the trap of naming the company but I'm sure you'll figure it out.
Anyway, this persons job was to infiltrate various groups and find out when there was going to be protests in front of the the retailers stores so the retailer could warn the stores and remind them of how to behave. Don't engage, etc etc. Fairly benign stuff.
Except that one time when it that company decided to pass on the information it got about a large protest in Seattle to the police there.http://gawker.com/5850054/meet-the-guy-who-snitched-on-occupy-wall-street-to-the-fbi-and-nypdUPDATE:
Oh ho, apparently this dude has an account on Google+. So +Thomas Ryan
, anything to say in your own defense?