It looks to me (and I'm only a librarian) that for a long time we've been making several mistakes.

First, "innocent until proven guilty" doesn't apply to the police. It applies to court proceedings, and only in criminal cases. Defense attorneys will work with every (legal) means they have to prove their client not guilty; the prosecutor, representing the people, will do the same for guilt. The judge is there to referee and insure fair administration of justice.

Secondly, the police enforce the laws. They do not assume guilt or innocence, but follow the trail of evidence to its logical conclusion. At that point, the prosecutor and the defense attorneys take over. If you think the law is wrong or a bad law, change it by legislative action or judical review -- cops, prosecutors, defense attorneys and judges have as much say about the content of the law as the checkout clerk in the supermarket has about the prices the store charges.

Thirdly, the fact that I wouldn't provide the police of any sort with certain library records (and not all library records are privileged) UNLESS they had a warrant or court order for the records doesn't mean that I wouldn't work with the police in other matters. I can and I have. And if the police were to come in with a warrant for your records I'd provide them -- just as you would provide tax records if the IRS came 'round with a warrant.

Yeah, yeah, I know that there are bad cops and bad lawyers and bad judges. I've aware of King Richard I's remark that "the police aren't here to create disorder, the police are here to PRESERVE disorder." I've aware of railroaded prisoners and that Joe Hill was innocent. But unless we work towards an ideal we'll never achieve anything except to trudge around in the same old vicious circles.