Re: My Passphrase
"If the police enters your home with a valid search warrant, _any_ evidence of any crime can be use against you, even if you were innocent in the original case."
Not quite. One of the conditions of a search warrant is that the police must list specifically the item(s) that are to be sought. ONLY those items can legally be seized under the terms of that particular search warrant. Going beyond that can disqualify the evidence. It's been shown on more than a few police procedurals.
HOWEVER, when police discover unrelated criminal evidence, that doesn't preclude them going out and getting ANOTHER search warrant stating the NEW evidence they wish to seize. A legal search can itself be legal grounds to get a search warrant for newly-discovered evidence.