That's what I'm afraid of: once the citizen patrols start working public land instead of privately owned land, it's their word against the illegals or the law, and will probably find themselves frequently arrested and bring down the wrath of agencies on the other patrol groups that work strickly on private ranch land. Individual citizens have a right to protect their private property, but the law starts to get fuzzy on public land.
They will probably have to document everything meticulously with video, including night-vision imagery and (if they got it) tactical radar imagery showing a) the GPS-located position of the radar emitter and b) targets crossing the border.
Of course, everyone I know can just dip right into his IRA and come up with all that equipment........
A lead-pipe cinch, in other words.
If what dirtboy said is true, then they don't have a right to protect themselves or their property; they only have a right to call 9-1-1 and then maybe some LEO will do something about it, in his abundance of discretion, after some suitable period of time passes during which your family become corpses.
You have the right to remonstrate in strong language, and to urge the felons on your property, in your best imitation of Judith Martin starchiness, to leave your property posthaste!. Then, after they stop laughing, you are in God's hands -- and theirs.