Which means that Expedia keeps a record of citizens who use their site,
and what the citizen does on the site,
and provides those records to government agents.
Fine, in this case they caught a killer.
Still, I don't trust this weapon in the hands of corrupt men.
Fair enough, but remember this: Every weapon is dangerous in the hands of a corrupt man (or woman, come to that).
It's not the weapon, whatever its nature or type, but the wielder of whom we should be wary.