"encryption blocks justice"
Which kind of justice exactly ?
The kind that bursts through the door, trashes your appartment/house in search of weapons/drugs/illegal-substance-of-the-day then gives you a full cavity search to be sure they missed nothing, leaving empty-handed with nary an excuse for having violated your life, your body and your privacy under the pretense of "securing the Nation" ?
Or the kind that gathers intel, checks it out, asks for warrant to place under surveillance, gathers direct observational data and, when all indications are you do actually have a bomb lab in your basement, then comes crashing into your life at 6 A.M. sharp to ruin your evil plans ?
Once again encryption is being paraded as the tool terrorists use. Terrorists may indeed use it, but in Paris they did not. As a French national, I am particularly looking forward to the explanations of how these nutjobs got through on plaintext SMS. But in any case, I feel that we, as a society, must absolutely stop relying on computers to discover and gather information on suspects. SigInt has its limits, and they appear to be rather drastic.
I would much rather have all entryways to major cities equipped with metal detectors able to sniff out weapons-grade metals and sending an automated alert and license plate pic to Police HQ(*). I think that would honestly be a lot more efficient because, however long the scum takes to plan, whatever the encryption they use (or don't, as the case may be), they still have to show up physically, all geared up, to accomplish their despicable mission.
If you can catch them while they're still in their car, you can very much limit the damage they can do - contrary to the situation today where we have a few officers sifting through petabytes of useless data and not getting the intel they could actually use.
Alert from the Porte d'Auteuil ? It's a black Seat with four bearded guys dressed in black ? Time for the rapid intervention RAID team. Start the roadblocks and we'll get them !
* - of course, maybe a better alternative would be an automated 80cm-thick steel plate that pops up in front of said vehicle. Vehicle crashes into it, everyone inside seriously injured, cops and medical services just need to mop up. YMMV.