The number of airports is consistent with the number of people. But who in his right mind would want to work in TSA if they can find a respected job elsewhere? Israeli screeners, on the other hand, are respected.
TSA is $8billion, FBI is $9billion, DHS is $55billion.
As the US military uses less air conditioning in Afghanistan, that should free up at least a couple billion.
I imagine if you paid what it really cost to have screeners with that level of training we'd be talking about a pretty hefty increase over the FBI. Mind boggling.
[edit]
Probably to ICE for government provided IP protection and enforcement without due process.