Yes, unless the card specifically says enchant a creature you control. This is actually a great strategy with cards like Darksteel Mutation to neutralize an opponents threat without letting them recast it
Same cost to play, cheaper to activate, same discard-to-tutor effect, but it lives on a 2/2 body that requires summoning sickness to wear off and can be removed before you get value
You have very little wiggle room for cards that don't interact with the board directly, so keep things like pure card draw spells and discard spells to a minimum
Stonehorn Dignitary makes a target opponent skip their next combat phase, and if you repeatedly blink or recur it, that player will never get to attack
On the flipside, you have creatures and enchantments that can give hexproof to other creatures, but they can still be targeted