Either one of the TLAs (FBI, CIA, or NSA) or a third-party company monitors the social media of security researchers associated with some big name firms. The reason I know this is a buddy said they were out at some DEF CON party and taking pictures with people. Just after the event, they got a call from their boss that they, in turn, got a call from their boss who got a call from some government-affiliate that the person they took a picture with was a "bad dude" and it would be wise to not associate with them. It sounds like a made-up conspiracy theory/paranoia shit, but it sounded truthful by someone who wasn't in the business of making shit up. My impression was it's creepy and promotes chilling effects on meeting people for fear of harming one's employment.