Seriously scary stuff. I was doing 40-50mph on that decent a few weeks ago on Vale Ride, which was a joy after the 15 mile climb to get up there. That's a nasty bend though, so the consequences could have been horrific...
Becoming very common. A race in Surrey was attacked by pins. Got quite a lot of attention, I went on BBC Surrey radio to talk about it, seems this sort of thing is frowned upon by the authorities.