Some of the videos that freak me out are people that start having a panic attack while rock climbing or something that doesn't have a harness or just extreme heights.
If you are on the side of a mountain and your fingers and your feet are the only thing holding you to the cliff side and you get stuck, damn....
I've never lost any function during a panic attack. Weird.
Normally a result of anxiety disorders a "proper" panic attack tends to lead to a near complete shut down.
It's... A little scary to watch it happen. Especially since it's a little different for each person, but also because there's often little to nothing you can do that won't possibly make the attack worse. I've seen a few, but the worst was watching my ex have one and being completely unable to comfort her when any other time just a light touch would make her relax.