This is the name given to the armed guards that work the perimeter of Area 51. They are affectionately named so due to their camouflage-colored clothing.
The important thing to remember about Cammo Dudes, is that as long as you are where you are supposed to be and doing what you are supposed to do, they will most likely leave you alone.
Their job is to monitor activity around the base and to make sure people aren’t trespassing. On that note, they do have the authority to shoot and kill anyone who is doing so.
One important thing to remember is that these people cannot have their identity recorded, and allegedly will lose their jobs if their photo or video of their face is taken, so keep that in mind as a courtesy when taken pictures of the area.