On Skyline there's a glitch that allows you to fly around the map and glitch inside buildings. It happened to me last week and I assumed it was a random bug, but i've since read other complaints here accusing people of hacking doing it, so I assume it's reproduceable.

I'm not sure exactly how I did it, but I was on the lower level of the helipad area (can't recall if I was sprinting or jumping or not) and just took off until I reached the height of the floor of the roof area where the water towers and elevator shaft are, and I flew through any obstacles I came across, and could go anywhere on the map, just no longer up or down (jumping no longer worked).

I wasn't invincible and still could be killed, but obviosuly it gave me a huge advantage! Be nice to see this patched before someone works out how to do it all the time.

agreed, idk if there is an official bugs and issues thread. try posting it there to be sure that crytek sees it!