It's more palatable to the people if they can hang you with your own words. No one is going to care if they can 'prove' they saved the people from a danger. On

It's more palatable to the people if they can hang you with your own words. No one is going to care if they can 'prove' they saved the people from a danger. On top of that, the people will be more willing to accept any 'proof' they intercepted when they know the government is intercepting everything.