Area 51 is THE most heavily guarded facility in the United States, if you went in and tried to get some information you could be shot and killed without question. The base's security measures include trip wires, infrared radar, guard towers, tanks, aircraft, ground troops, drone gun turrets, not to mention the whole area is a No Fly Zone; any non-US military aircraft is shot down without any warning. If you ask me, both H.E.A.T. and the conspiracy theorists entry to the base shouldn't have been that easy. Plus, any surviving intruders that caught at Area 51 are immediately arrested, interrogating, most of which disappear without a trace.