The bandit will ambush alliance automatically. If you are Horde(like me), you're going to have to spam the macro referred to earlier (/target blood elf bandit) Also when you use this macro, Furbolgs might be targeted by the macro, but I just ignored it. I found 4 Blood Elf Bandits this way at the following 3 locations (43,63) (35,65) (32,62). The bandits are located off to the side of the road a bit, mostly behind bushes. I've only had one respawn (rather quickly) so I'm guessing they have random spawn times. I found the mask on my 3rd kill. I've been looking for another bandit for an hour and none else have respawned.  Hope this helps everyone. Enjoy.

Poseidon
Level 32
Troll Rogue
Arthas