My proposed responses to these questions, if asked by TSA as part of a domestic trip:

"I refuse to explain why a ticket was purchased for me to travel from here to there. I object to this unconstitutional interrogation. Am I free to leave?"

"I refuse to provide non-material information that has no bearing upon the potential security risk my presence presents represents to an aircraft. Am I free to go?"

"Your request for details of this financial transaction will be complied with, as soon as you can articulate probable cause and produce a warrant compelling me to answer such questions. Am I free to go?"

"My travel plans, and the plans of any potential travel companion I may be flying with, are not germane to your ability to protect our aircraft from introduction of WEI. I will, however, comply with this request as soon as a warrant is produced compelling my cooperation. Am I free to go?"

"My travel plans are private and personal. You are acting as an agent of the government, and as such have no right to request this information unless it is part of a criminal investigation in which I am a suspect. If I am suspect in a criminal investigation you are involved with, I demand to know immediately so that I may retain and consult with an attorney before this interrogation continues. Am I free to go?"

"Until I decide to leave."

"Unless you can articulate probable cause for this line of questioning, I respectfully refuse to answer these queries as they constitute an undue interrogation by a government agent. If you can articulate a reason for asking these questions, I demand an opportunity to speak with counsel prior to answering them, and prior to this interrogation continuing. Am I free to go?"

"Please explain how my return date has any bearing upon the security risk I present to the aircraft. How does knowing this date help protect the aircraft from introduction of WEI? If you are incapable of explaining how this line of questioning does not violate my rights, then this interrogation is over. Am I free to go?"

Hopefully asking about being free to go trips them up to say "no" at some point. That hopefully sparks a lawsuit against the screener personally for false arrest, and against the agency. (I'm beginning to think that one appropriate strategy to hurt TSA might be to sue screeners individually. Sue them for small amounts of money - enough to cover your costs in small claims court, but not enough to make it worthwhile for them to take a day off to go to court. In the end they lose no matter what - don't take a day off work, lose the lawsuit and have a default judgment entered against them; take a day off work, and maybe they win, but it still cost them more to defend themselves in losing a day of vacation.)