Batman: Arkham City - Joker's Snipers
SPOILER! Hunt for Joker's snipers with a little help from game guides editor Kurtis Seid.
You can also use the grapnel takedown or ledge takedown, their loud, but your gone before the other enemies can target you. There's also the option of a remote batarang, turn the thruster on and you lay someone out.