Structures such as Terran Missile Turrets, Zerg Spore Colonies, and Protoss Photon Cannons allow the opponent to see the units cloaked by the Arbiter, making it a moot ability.
Structures such as Terran Missile Turrets, Zerg Spore Colonies, and Protoss Photon Cannons are always built for fear of such an attack. All the above structures allow the opponent to see the units cloaked by the Arbiter, making it a moot ability.