WordNet (r) 3.0 (2006):

potshot
    n 1: a shot taken at an easy or casual target (as by a
         pothunter)
    2: criticism aimed at an easy target and made without careful
       consideration; "reporters took potshots at the mayor"

Moby Thesaurus II by Grady Ward, 1.0:

65 Moby Thesaurus words for "potshot":
   aspersion, blind bargain, bowshot, bullet, cannon, chance at odds,
   charge, cock, crack, criticism, cut, detonate, detonation, dig,
   discharge, drop, eject, ejection, fell, fire, fire off, fusillade,
   gambling chance, gibe, gun, gun for, gunfire, gunshot, hit, insult,
   jeer, let fly, let off, load, matter of chance, pelt, pepper,
   pick off, pistol, plug, pot, potluck, potshoot, prime, random shot,
   riddle, salvo, shoot, shoot at, shoot down, shot, shy, sideswipe,
   snipe, sporting chance, spray, stoneshot, strike, take a potshot,
   tattoo, torpedo, toss, toss-up, touch and go, volley