posted the other day, personal story:
Couple of years back I went to the zoo one fine morning. I was walking past the African lion area- which has a glass-front area like that in the video- when a security guy on a bicycle rode past and said "Watch this!"
He rode along the front of the lion glass and one big female suddenly appeared around a rock, belly-crawled to the front and stared at him. He stopped by me and said the others usually ignored him, but that one would almost always come sneaking down to the glass or the mesh(on the north side) to watch him. Ever seen a cat getting ready to pounce on something moving? Upgrade that look to a 250-pound or so lion and you've got it; she wanted him, bad, and just stayed there, motionless and staring. Hell I know how strong that glass is and it still made me nervous.
So when I see a critter trying to eat a kid on the other side of the glass, and people laughing about it, it bothers me.