Enchanted creature's activated abilities can't be activated.
{1}{W}: Attach Detainment Spell to target creature.1 Bind the mind rather than the wrist, and you stop the intent to harm before it starts.
Illus. Darrell Riche
9/25/2006: Detainment Spell prevents mana abilities of the enchanted creature from being activated.
9/25/2006: Morph isn't an activated ability, so Detainment Spell doesn't prevent face-down creatures from being able to turn face up.
9/25/2006: Responding to a creature's activated ability being activated by moving Detainment Spell onto that creature won't affect the ability that was just activated.