> 1. They said that FB captures 99% of those illegal activities by themselves. What makes us think that government will be able to capture that last 1% on their own?

To stress even more on this point (I have to also FULLY agree with the second), what evidence is there that lack of encryption will even make it easier to capture this 1% more. Pareto is a real thing. I'm not convinced there's an easy answer to capturing the last 1% and that it can be done with minimal resource allocation. That's where I start being suspicious. The back of the envelope math doesn't work out.