150 years ago, President Lincoln found it necessary to hire a private investigator - Alan Pinkerton for protection.
That was the beginning of the Secret Service.

Since that time, the federal government has produced a large number of multi-letter agencies such as: FBI, CIA, INS, IRS, DEA, BATF, etc.
Now we have the " Federal Air Transportation Airport Security Service". Cant you see them now, these highly trained men and women in their black outfits with jackets saying across their backs: F. A. T. A. S. S.  

The FATASSs are of course supervised by a special section of the Home Land Security Section known as: Airport Security Service Home Office Logistics Enhancement Section or the A.S.S.H.O.L.E.S.