Roswell's most famous Area 51 is where (resumably) Stealth technology was developed.
The flying saucer stuff proved an excellent cover for years as the Nazi designs were reworked to give us modern stealth technology. This was all Top Secret stuff; and yes Virginia, lethal force was something they were willing to use to keep you away. If you search my site for DARPA you can find several long posts of the kinds of things that have been funded and have gone on- and continue to go on- (presumably) in places like Roswell.
I find it very interesting and embarrassing for DHS that private contractors working at this site are bringing in cheap labor without appropriate security clearances under the nose of the one of the supposedly most secure areas of the country.
But I suppose I shouldn't be.
After all, if a private contractor sells top secret technological information to another government, well, its not something they wouldn't have figured out eventually.
On the other hand, if CNN announced, for example, those glowing spacecraft were really experimental stealthed fighters painted with radium at a density of a Curie per square cm, some civilians who understood what that meant might really get uneasy.