I have heard Alex Jones and others like him talk for a long time that there are government trolls on the web spamming message boards. I don't doubt that this is true to some extent.
Police for example have been known to send in civilian police officers in demonstrations to act as agent provocateurs. So it's not unreasonable that they work the same way on the web.
What I'm looking for is credible sources to back up stories about government employed people spamming message boards on the web.