No, the nasty mark on my chin was not caused by a human punching me. It was caused by a pony...
There are all sorts of sayings about ponies being evil. My favorite is this one:
"The closer to the ground, the closer to..."
You can guess which word I'm redacting there.
Here's the thing about ponies.
Ponies are not as genetically altered from wild stock as horses. This has its good aspects - they live longer, tend to be healthier, can carry or pull quite a bit more weight in proportion to their size, often have better hooves, etc.
However, they also tend to be just a tiny bit less...uh...cooperative in natural personality. And many of them seem (I stress seem) to have a wicked or even actively malicious sense of humor.
What happens then is that because of their small size they are often given to children to ride and handle. No matter how talented, children will never have the perseverance, maturity, emotional control or experience of adults (Yes, I know some teenagers who are more mature than many adults, but the smallest ponies are being dealt with by pre-teens).
If the adults around aren't on the ball and working with the kids, then it can rapidly degenerate into a situation where the pony is in charge - and you've created "a monster that will not obey."
A spoiled horse is bad. A spoiled pony is terrible - and there are far more spoiled ponies. Ponies need to be fairly regularly handled, and if large enough ridden, by adults so they don't think they can get away with, oh, I don't know...
...pulling people off over their head by the reins. (I was actually surprised he was strong enough to get me that way - usually I laugh when they do that :P).
And sometimes, of course, they get away with stuff, like little dogs, because they're just this cute. (Neither of those two are evil to my knowledge).