> presumed innocence until proven otherwise with evidence.
That's exactly the problem. Lawful surveillance is one of the most fundamental means of gathering evidence. If you take away that, then in a lot of cases you take away the ability to prove guilt.
You offer no support for the claim that police would be useful in a world where all telecommunications are impenetrably encrypted with no means for lawful intercept. If "Plain Old Telephone calls" are the only interceptable means of communication by police, then you might as well rename them the "Plain Old Police", since they would be largely ineffective.
I have not argued for rescinding any rights whatsoever. It is you, I would argue, who is arguing for rescinding the police, which are an essential part of a lawful society.
The flaw in your reasoning is that while individuals are protected from self-incrimination, no such right extends to third parties. Nor should it. The 5th amendment does make it harder for police to prosecute people, but with the power to compel other people to testify, to have service providers turn over records and surveil with proper judicial oversight, and so forth, it has been judged over the centuries to be a fair balance of powers.
To block all police power to surveil under any circumstances would substantially cripple their ability to gather evidence.
And so the question remains: If you feel lawful intercept of communications is never justified, how would one go about gathering evidence of a largely communications-based crime such as child pornography or plotting a murder?