I don't think that any of the surveillance powers that the state is demanding with respect to electronics actually map that neatly to what was possible before electronics emerged. We're talking about conversations rather than physical effects, and it's not like you could obtain a warrant to retroactively obtain the contents of a conversation a marijuana dealer had with his client yesterday: once the vibrations were gone from the air, that data has been erased irretrievably. To listen in on the conversation you actually had to go there, which naturally forces you to be judicious with your surveillance powers by virtue of limited resources, whereas the electronic version scales indefinitely. On the other hand, as long as the people who are of interest to law enforcement still exist in meatspace themselves, everything that used to be possible is still possible: just as you could obtain a warrant to bug someone's room to listen in on a conversation, you can obtain a warrant to bug someone's room to observe their phone (or bug the phone itself, with physical access! Maybe that would be one rationale to finally force Apple to make its phones "repairable" by individuals :)).
