I continue to be baffled as to why Greyhound doesn't tell the TSA "This bus depot is private property--no warrant, no searchie". (Of course, this would only work where the Greyhound station is, in fact, private property, which is not always the case.)

Especially in areas of the country (northeast) where they're competing with Amtrak, tiny-haul flights, and other bus carriers. Heck, it's a marketer's dream come true: "Go Greyhound and leave the TSA to the skies."

Any other business would do this. If a cop stationed himself at the entrance to a mall and started demanding photo ID of patrons entering and leaving the mall, the mall management would tell him to pound sand and come back with a warrant.