[stefantalpalaru]

> It is probably more useful for blackmail than in prevention - this is a good point. But it is far from obvious that it is ineffective in the letter case. If you believe that it is obvious - then please explain.

Have you watched the news these last few days? Known extremists managed to get AK-47s and explosives in the middle of Paris, at the highest alert level of a military-on-the-streets Vigipirate program, while the borders were closed and the city's security was further elevated for an upcoming international meeting about climate.

They were known to law enforcement, they communicated over cleartext intercepted channels, they lost themselves in the noise of tens of millions of people joyfully filling some Stasi's storage units with their private conversations.

And all this less than a year since a similar event lead to the incompetents asking for even more data that they can stash for after the fact investigations. So there's a valid use: finding out, in retrospect, exactly how they failed to do their jobs. And maybe ask for even more funding, even more privacy invasions, even more power.