It did happen. I was a member of Friends of the Border Patrol last year. The name of the private ranch that served as our HQ appears in Spanish-language Mexican reports on "vigilante" activities. The only one who know of this location was the Border Patrol who were entrusted with knowledge of all of our activities. The link to the reports appeared on the May 10, 2006 Drudge Report.
Yes, I saw that and it was not true. There was a thread somewhere about how it and I'm sure someone knows where it is but I don't feel like looking for it. And the MM announce their locations, don't they?