In snapshot 14w07a, an item frame summoned and placed with the invulnerable:1 property has different and undesirable behaviour. It's not clear whether this is deliberate or not - this change is not reference in the change log for 14w07a.

1. An item cannot be placed inside an invulnerable item frame even in Creative (though the item can be specified via tags in the summon command)
2. The item in the frame can no longer be rotated (again, rotation can be specified when the item frame is summoned, but the player cannot interact)

Semantically, "Invulnerable" could include the meaning "Cannot be interacted with in any way"...however the behaviour is not desirable from an adventure mapper's point of view as it means we can't have interactive item frames (with the new redstone functionality) that aren't destroyable by the player!

This just serves to highlight the very strong need for adventure mappers to be able to have an easy way to implement item frames for puzzles etc. that cannot be griefed in adventure mode. Up until 14w07a, it was at least possible, though horribly messy, with the summon command to do this, but this apparent change in 14w07a seems to be a step backwards again.

Looks like a property such as "Rotatable:<0|1>" would be a start if this behaviour is deliberate, though this still doesn't solve the problem of the difficulty in working with entities like paintings and item frames in creative for adventure mapping.