UK engaged in mass telephone/fax taps during the Troubles with wild abandon.
http://www.lamont.me.uk/capenhurst/original.html
The inability to monitor suspects telecommunications is a very recent phenomenon. Governments had that ability more or less from the moment Bell started building his system.
First, for actual suspects there never was any inability to monitor their telecommunications. (and any legal inability never meant much to the agencies doing it).
This is not about this (targeted taps), it's about tapping everyone and at all times. Which they also do, but now they want to make it official and sanctioned.