Makes you butt pucker

[ZLP955]

I have been up many tower cranes back when I worked in city high-rise construction, but that video made me wince and look away a couple of times. Those guys are nuts.
Aren't they part of a global group of fellow 'enthusiasts' that film themselves doing extreme stunts? Saw a similar video where the guy got into and explored a whole series of London Underground tunnels that'd been sealed and abandoned since the war, all in pitch darkness and no chance of rescue if he fell or got trapped.....