This might be a very naive question (I know nothing about these things) but is it possible that a piece of information obtained by such illegal means could be used to aid an investigation without using it as evidence in a court?
For eg. Anonymous hack a child porn site and dump the database, which they send to police. I can't see an easy way how the police can use that information without it coming up in court as to how they got the lead in the first place. If they were to subpoena that persons email account or apply for a search warrant, the probable cause would need to be something that the police discovered independently.
The database would be a good source of leads, which would have to be worked separately.
It is very possible for something to go wrong. Everybody needs to know about Operation Ore:
http://en.wikipedia.org/wiki/Operation_Ore
US feds sent a database of users of an online payments service that was servicing child porn sites to police in the UK. What was lost in the communication, or what the US feds didn't know, was that the same payment service was also being used by legal or legitimate adult sites.
The UK police treated each user as a child pornographer, and made 3,700+ arrests out of the 7,000+ suspects. Most of these people were innocent, and the dragnet caught up teachers, lawyers, police officers, etc. and resulted in 33 suicides. It took these people a very long time to have their names cleared, and most have never recovered.
I'll bet some of them even had nothing to hide. If you just take into account the fall-out from this particular incident (which should have led to a few more heads to roll) then that alone is an excellent reason why dragnet style surveillance is a really bad thing. It leads to a large number of false positives and those in turn will have very negative real world consequences for innocent people that would have otherwise been able to just continue to live their lives.
Law enforcement should be done with the scalpel, not with the blunt end of an axe.
Today it seems the government believes it is better for 100 innocent persons suffer than to allow 1 guilty to escape....
Slavery was a grave error of that time. But it doesn't devalue the other, unrelated principles of yore as presented in that Ben Franklin quote of the GP.
But the fact that, centuries ago, non-whites and women weren't considered Persons with a capital P still doesn't negate the fact that the USA has abandoned its most important foundational principles (rule of law, fundamental and inalienable civil rights, freedom of speech) over the past 12 years.
I'm not claiming that the USA unhypocritically perfectly adhered to its stated values in the past. We broke the law and tortured people in WWII, in Vietnam, and in the guerrilla wars of South America, too. But you had to do those things below the radar. There were eventually consequences, if it was found out.
Now the US government disappears its citizens, or kills them (and whatever men, women and children that happen to be nearby) right out in the open, and the President goes on TV to talk about what a weighty thing it is on his conscience for him to approve all these murder lists in advance.
It's true, as some point out, that unconstitutional, illegal, and immoral things have always been done by the US government (and pretty much any government). However, it seems to me a fundamentally different thing when it is done without even pretending to adhere to the law or the constitution, in any more meaningful way than Nixon's claim that "when the President does it, that means that it is not illegal"[1][2].
[1]: http://en.wikiquote.org/wiki/Richard_Nixon
[2]: https://www.rutherford.org/publications_resources/john_white...
We shouldn't let past abuses excuse future abuses.