Turn off the flow of your data to them!
Facebook Disconnect blocks all traffic from third-party sites to Facebook servers, yet you’ll still be able to access Facebook itself.
"It was supposed to be a war fighter unit, not a geek unit," said task force veteran Jason Healey, who had served as an Air Force signals intelligence officer. A fighter would understand, for instance, if an enemy had penetrated the networks and changed coordinates or target times, said Dusty Rhoads, a retired Air Force colonel and former F-117 pilot who recruited the original task force members. "A techie wouldn't have a clue," he said.
Yeah, and this has been the case since, oh, 2001? Well, at least it seems that's when it started to be enforced more strictly. I've heard rumblings that the administration was going to change it, but who knows how likely that is.
Hmmm... I wonder if we could correlate the US's drop in space proficiency with when ITAR for space components started?