Part of the money is spent on security groping.
From a Vanity Fair article:
Since 9/11, the U.S. has spent more than $1.1 trillion on homeland security.
a large number of security analysts, this expenditure makes no sense.
The vast cost is not worth the infinitesimal benefit. Not only has the
actual threat from terror been exaggerated, they say, but the great bulk
of the post-9/11 measures to contain it are little more than what
Schneier mocks as "security theater": actions that accomplish nothing
but are designed to make the government look like it is on the job. In
fact, the continuing expenditure on security may actually have made the
United States less safe.
Read more: Smoke
Screening – As you stand in endless lines this holiday season, here’s a
comforting thought: all those security measures accomplish nothing, at
enormous cost. That’s the conclusion of Charles C. Mann, who put the
T.S.A. to the test with the help of one of America’s top security
experts. Vanity Fair>>