LEO can and does get warrants to do intrusions for identification purposes
https://secure.wikimedia.org/wikipedia/en/wiki/Computer_and_...
They also have a high standard of evidence, before they can go to trial. Otherwise, they are better just observing, and waiting for more evidence to reveal itself. Once you shoot your mouth off, the suspect stops making mistakes.
They admit in the document to "backhacking" the targets, which already puts them at an advantage against law enforcement.
edit: s/probably/probable (it's late)