Okay, maybe completely locking out someone from using it isn't necessary, but there should be some sort of effect.
I'm thinking LOTR. Frodo can use the One Ring against Sauron's minions... But there is a cost. There is corruption that takes place.
The Sword of Justice is blessed and given Tyr's power. It may not have intelligence, but it's Tyr's power on the blade. It should have some sort of effect on people.
I mean, if my Cleric of Selune were to use a Dark Justiciar magic armor blessed by Shar, I'd expect some sort of corruption or influence or something to show that Shar was messing with her.