Bulbapedia: "The Dark type, along with the Steel type, was introduced in Generation II in order to balance the previously overpowered Psychic type. As such, Dark is designed to have a key immunity to Psychic moves."

Love the pic though :p

Although, one must wonder how something can "resist" being lifted by a move like telekinesis. Video game logic, amirite?

I checked on it an it doesn't go into depth, but I imagine it would be like most animes where when one has an immunity, it would be like Greninja (or other dark pokemon) have a "dark" aura, where the psychic pokemon would have their own aura etc, and the dark one would resist the "pure" one. So no psychic attacks nor techniques would be effective. That's my opinion on the matter :3.

Two words: Miracle Eye

That's completely retarded. I can understand introducing the move to make things more balanced, but that's like making a ground or rock pokemon susceptible to electric attacks.

Plus Miracle Eye is a psychic move, so it shouldn't work in the first place. But while it exists I guess it would work.

rock types take normal damage to Electric type attacks, I Could also bring up the Ring Target, Greninja's hidden ability, Delcatty's Normalize and Inverse Battle

And if Foresight, Odor Sleuth and even Attract (all Normal Type moves) work on Ghost types, then I don't see why Miracle Eye can't effect Dark Types
(Please don't start a Comment war...)

This is why it's not always wise to run Protean.

That is why you make him a fast little fucker and give him a good spread of move-types ;)