Yes yes they are. When I saw the video of the jump from the Antennae I cringed at the thought of what would happen if they hit one of the support wires.
The guy jumping from house to house is insane with no other words to describe it, while most other jumps could be somewhat calculated I have no idea how one can calculate whether or not he would clear the 20ft or so gap with no running start while falling a good 40 ft.
Launch yourself from the moon straight towards the Earth with just a parachute to land you.