Iran "Captures" U.S. Drone

I have to ask... How and why? How did they get their hands on a U.S. drone aircraft (in one piece) in the first place, and why was it not outfitted with a fail-safe internal or operator remote-control destructive device if these drones are such a big deal? We have the technical capability for either... or both!

The other question that crossed my mind is:
If the RQ-170 Sentinel drone's stealth technology is so relatively unimportant that we don't bother to protect it properly, why the heavy media coverage? Is it truly newsworthy, or is it "much ado about nothing" on an otherwise slow news day? I think the stealth fuselage itself would be worth protecting.

Just curious...