Blind Obedience (GTC) from Gatecrash, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Seb McKinnon
• Card Text:
  Extort (Whenever you cast a spell, you may pay (W/B). If you do, each opponent loses 1 life and you gain that much life.)
  Artifacts and creatures your opponents control enter the battlefield tapped.