The video feed and the the guidance connection are two entirely different animals. The vid feed is open for ease of access to ground troops and whatever friendly forces are in the area. They've known about this for years, but it is not in any way a danger to the UAV.

The guidance systems are heavily encrypted and were not hacked, and it did no land anywhere, it crashed. The Iranians were given tons of Russian jamming equipment for just this sort of situation. When they knew there was a UAV in the area they turned all their jamming equipment to max to that every signal was blocked and you couldn't even make a cell phone call if you were on top of a cell tower. The drone lost connection, and did a circling pattern while it tried to regain connection with home. When it ran out of gas it crashed (mostly intact) and now the Iranians have a massive propaganda tool and have probably already sold the parts to China and Russia so they can try and reverse engineer things.

They in no way "hacked" that drone.