The minutemenproject is a group, 500+ strong and growing, forming to patrol the US/Mexico border. They plan to come together as a group and spend the month of April patroling the border in AZ.
According to their website the minutemen will represent 46 states.
FAQ page has this
Q:
Do people carry firearms, or just observe without protection?
A:
The Minuteman Project is neutral on this issue. It neither encourages nor discourages the "open carry" laws of the state of Arizona>
Another choice quote from the minutemen site
Most illegals will try to avoid confrontation if at all possible. They are more afraid of the "uncontrolled vigilantes" than they are of anyone wearing a badge.>
Get to know The minutemenproject their website is an adventure to say the least.
I found this story at Atrios, he links to this ABC/AP story