unless they examine all the data. Called "FISHING." Hence they have to get it.
Physical access too time-consuming and risky. You are assuming they have someone in their sites. This is normally not the case. They have to process tons of information from innocents to find one guilty--like the needle in the haystack. You tell me--How would YOU find him if you don't know where he is???
And, of course, this must be done without chance of discovery, without risking exposure (publicity might be created)and everything getting shut done.
And since we are here on forum this venue may be used to steer everyone in the wrong direction. Just to let you know...
Keep Up with TechRepublic