Back in 1997, John Ashcroft was a Senator. When the Clinton administration wanted governmental control over universal keys to decode encrypted transmissions on the internet, Ashcroft objected vigorously -- in part on Fourth Amendment grounds:
Why . . . should we grant [the] government the Orwellian capability to listen at will and in real time to our communications across the Web?
The protections of the Fourth Amendment are clear. The right to protection from unlawful searches is an indivisible American value. Two hundred years of court decisions have stood in defense of this fundamental right. The state's interest in effective crime-fighting should never vitiate the citizens' Bill of Rights.
That's a slightly different point of view than the one he espouses today. Ashcroft's 1997 broadside can be read in its entirety here. (Kudos to TalkLeft for this magnificent find.)