However, this is actually being done (as of 2009) by immigration vigilante Glenn Spencer.

http://exiledonline.com/border-wars-a-day-in-the-life-of-a-v...

  He started American Border Patrol seven years ago after 
  retiring from a lucrative career as a military think-tank 
  analyst and oil prospector, trading in the chance of a slow 
  and cushy death aided by golf and bingo for the life of a 
  border vigilante. He also gave up his wife and his daughters, 
  who broke off all contact with the man after he moved to the 
  desert. “We’re on different sides of the issue,” he told me. 
  But it might have less to do with the issue than his decision 
  to sink his entire life savings into this high-tech security 
  dream.