> You simply can't trust the government to respect boundaries that they created but have the ability to breach, especially when it can be done completely surreptitiously.

No, but in a functioning democracy we can vote them out. Democratic governments by definition have an large concentration of power, otherwise they can't fulfill their functions.

But this is bound by laws, time, and the ballot box. Surreptitious (warrantless) government surveillance should absolutely be illegal. Searches with a legal warrant (through an accountable, non-abusive, warrant granting judicial system) are absolutely necessary to gather evidence for prosecution of crimes to take place. Without trustworthy investigation and prosecution of crimes, the social contract will fail, and this has already started happening in many areas, as we are seeing in a way right now

However, this goes both ways - the populace should get far more transparency into the functioning of the criminal legal system - especially in to the training and conduct of physical law enforcement (police officers).