The Terrorists are the ones in charge
re: "backed warrantless data collection in the name of defending us from terrorists"
The people breaking the law by spying on people without justification are the real terrorists here. They are destroying the civil liberties of the entire world. Terrorists as they define them might blow up a few cars. I can tell you that I have *never* had a fear of the people they are supposedly protecting us from but I definitely have a fear of them.
There is no technical impediment to making it possible to retroactively inspect every single transaction to occur anywhere and at the same time make it impossible for these weasels to inspect things with out valid permission from somebody trustworthy.
We record everything under a multiple key system and distribute the master keys to entities that are actually trustworthy. The more important the data the more keys required to inspect it. The bank, an insurance company, the local neighborhood association, the ACLU and local and federal law enforcement would all divulge keys necessary to trace and pinpoint a child predator or an actual terrorist about to trigger an atomic bomb. They would not all divulge keys for an illegal fishing expedition nor should they.
The people in charge who are saying this current surveillance regime is necessary are either technologically illiterate or morally corrupt; likely both. In either case, they are the very last ones that should be in charge of privacy. They don't understand it, they don't like it and they don't want it. Give them jobs where they can't do so much harm.