The Electronic Privacy Information Center filed a lawsuit last July over the TSA's use of body scanners, arguing that they violated the Fourth Amendment's protections against unreasonable search and seizure. Not surprisingly, the DC Circuit Court of Appeals disagreed. In a decision released earlier today, they dismissed EPIC's constitutional arguments against the body scanners, while agreeing with a smaller complaint that TSA failed to to "initiate notice-and-comment rulemaking before announcing it would use AIT scanners for primary screening."
On the question of whether or not the body scanner/patdown choice is "unreasonable," the court cited a 2001 decision in which the degree of "reasonableness" is “determined by assessing, on the one hand, the degree to which it intrudes upon an individual's privacy and, on the other, the degree to which it is needed for the promotion of legitimate governmental interests.” Judge Douglas Ginsburg, who wrote the opinion, concluded "That balance clearly favors the Government here."
This was going to be an uphill battle to begin with, and not just because of popular acquiescence to the security state. Back in the 1970s and 1980s, the courts set precedents that gave the government an extremely wide berth when it comes to airport security measures, deciding that "airport security checkpoints and loading gates are sui generis under the Fourth Amendment." The relative necessity of airport security procedures is hard to argue with, in part because the courts found that "Established search procedures are more valuable for what they discourage than what they discover."
Basically it's almost impossible to get the courts to overturn airport security procedures based on prior precedent, and to the extent that anything is going to change with the TSA it's probably going to have to come through Congress. I suspect most of them would rather complain and grandstand on the issue than actually do something about it, since no one wants to be vulnerable to accusations they made the next terrorist attack easier to execute.