I've had similar experiences, though, not with FBI, with DHS at DEFCON, to the point where I've been handed DHS business cards prior to hopping on flights out o

I've had similar experiences, though, not with FBI, with DHS at DEFCON, to the point where I've been handed DHS business cards prior to hopping on flights out of Las Vegas on my way home, and them calling me on my personal (non-work-published) cell phone a few days later.