[ENGNR]

The balance then is specific subpoenias for individuals authorised by a judge, with the individuals being informed after a reasonable period (say 9 months) which information was subpoenaed.

The library could potentially even give anonymised information that might give reasonable suspicion, eg let us know when someone rents these books together and we'll go get a warrant.

The sad thing is that the west currently has exactly this balance in place, but by pushing too hard everything is going to go underground or overseas. We're losing the exact capabilities we need to fight bad actors, thanks to the NSA's greed and short sightedness.