There have been lawsuits over the part the airlines still pay.
As directed by the Aviation and Transportation Security Act, the major responsibilities of airline passenger and baggage screening is now handled by our agency. To assist in paying for the increased aviation security, Congress provided us with the authority to charge airlines a fee equal to their costs of passenger and baggage screening in 2000, to the extent that the September 11 Security Fee was insufficient to cover the agency's costs for aviation security. Airlines pay one-twelfth per month of their 2000 screening costs to TSA.
http://www.tsa.gov/r...rcarrier_fee.shtm
Even though the screeners at airport security checkpoints in the U.S. are employees of the Transportation Security Administration and those fancy new see-through-your-clothes machines are technically paid for by the feds, the airlines still have to fork over hundreds of millions of dollars per year for security theater. Several of them claim the TSA is overcharging to the tune of $115 million. An appeals court disagrees.
See, the airlines used to be the ones that would foot the bill for airport security. After the TSA took over in 2001, it was determined that the airlines would continue to pay, but their share was capped at what the airlines spent during the 2000 calendar year.
http://consumerist.c...sa-screening.html