I don't understand how we can have such crazy double standards. If it's against the law, and there is evidence somewhere that I broke it, why is it outside the

I don't understand how we can have such crazy double standards. If it's against the law, and there is evidence somewhere that I broke it, why is it outside the mandate and allowance of government to enforce its access to it? Your examples are a bit contrived and evokes "incriminate myself" ideas that complicate it a bit. But what if it's more obvious? An email or private text message that quite explicitly says "yeah, I stashed the murder weapon in location xyz". We've all agreed that murder is illegal, currently using certain substances is illegal, fraud is illegal, etc. So why the double standard under the guise of "right to privacy"?