271.0 is a common frequency, used down here in Texas during TFRs around the Texas White House. "Bigfoot" is Air Force controllers at McCord AFB (Northeast Air Defense Sector), "Oakgrove" is Tindall AFB (Southeast Air Defense Sector). I've heard both here in Dallas, apparently they have remote transmitter sites all over. "Omaha" is a generic federal aircraft callsign but mostly used by Customs Border Patrol. F-16s will be doing the initial intercepts and pop flares, then if they fail to comply, most likely Customs Air will lauch a helo (Blackhawk) to follow the airplane to an airfield and have a chat with the violator. Violate a presidential/election TFR, and they get your "N" number, you can pretty much be guaranteed a 90 to 180-day suspension.
Mark
Mark