And it's not just gorillas - lions, whales, and countless other species are subject to unwanted attention from the sidelines of their enclosures. Earlier this month, The Dodo covered a video of a lion trying to attack a girl as she kissed the window. Unfortunately, being subject to taunts is the norm for many animals in zoos.
Add that to loneliness, lack of exercise and drastically different climates than their natural habitats, and it's fairly easy to see why captivity is a stressful environment for any animal.
The most direct way you can keep animals out of these situations is by not supporting the institutions that put them there. To learn more about efforts to keep wildlife in the wild, check out the Born Free Foundation, which aims to rehabilitate previously captive animals back into the wild.
You can find the full videos below.