I ride horses myself and I can say with certainty that this kid is an idiot. Also, they seem to just be trespassing on someone else's pasture or farm or whatever, even if this were his horses he'd still be an idiot. Though I'm kinda surprised he stayed on as long as he did, one thing that kinda disturbing is that they just laugh. Still kinda funny.
I'm not as much a fan of Megadeth as I am of Metallica, I don't own any albums, though I will eventually, but while they aren't as consistent, this is still a really good song. Skip to 1:13 for the music. In case you were wondering, the song (and video) is about aliens.
Megadeth -- Hangar 18