If you were sane, you would realise that restricting the right of billions of people to communicate privately, a right they have enjoyed for all the thousands of years of human history, is handing terrorists a complete and total victory far beyond any act of violence they could commit. The purpose of a government is not to prevent 100% of all crime and terrorism by locking every citizen in a straitjacket.

This also isn't even motivated by terrorists, but rather people daring to oppose the government.