Has the English police announced that FACT is a duly trained, sworn, bonded and licensed extension of their Legal arm? Have the English courts accepted this announcement from English Law Enforcement?
Without official training, bonding, licensing, let alone voting by the public, etc., you are merely giving one side of the case (FACTS) intimate information about the other side of the case - without doing the same for the other side. Shouldn't those being prosecuted have the same right to FACTS computers? After all, FACTS isn't without a "conflict of interests" in what they find - therefore, could hardly be deemed an unbiased or trustworthy source of information.
Considering what hackers can do to data, I'd say the moment the computers left the custody of the police, nothing on them could or should be admissable in court because of a break in the chain of evidence?
And, we wonder why people think there's a need for Anonymous and Wiki Leaks!