In Blade's Edge Mountains, right outside of Thunderlord Stronghold, there are a ton of Thunderlord Dire Wolves. These mobs are neutral to horde players, and Alliance has a couple of quests where they have to kill them. Well, in a very short quest chain, horde ends up with a quest called Protecting Our Own. This quest involves applying ointment to the wolves. The trick here is, when you see Alliance in the area farming on wolves, apply the ointment to as many wolves as you can. As long as the wolves are glowing red, they're technically "tagged" to you. If Alliance kills a wolve while they are red, you get the XP from it. It's also fun to scare them when you apply the ointment to the wolf they're fighting, lol.
Not super important or beneficial, but still kind of fun to piss off the alliance.