Where I live, the police have raided people's homes for protesting things Israel did. And when I was a victim of an actual violent crime, they kept saying how they should arrest me - according to demographic profiling, I was the perpetrator (I was there, I wasn't), all the way up to the courtroom where the actual perpetrator barely avoided prison time. So no, I don't really trust them to access my private anything. Any society with a hope of stability obviously needs some way to enforce laws, but this isn't it.
But even if the police where you live were perfect, handing them the keys to the internet wouldn't resolve crimes committed outside their jurisdiction.
I see why the idea is appealing to politicians, but even they ought to think twice about the risks inherent in third parties accessing their most private communications - given that whatever sides of the political aisles they sit upon they are likely to be much more interesting targets to better resourced assailants than us average schmucks.
