Christians, how can telling the future be a power given from Satan? (details)?

A lot of Christians say that people who can see the future have been given this power from Satan, and yet most of these same Christians say that the Devil can not tell what is going to happen in the future because he isn't omnipotent and/or omnicient.

If the Devil can't tell the future, how is he supposed to give us mere humans the power to do just that?
Greg, there have been quite a few Christians tell me that by "trying to see the future" or "divining the future" I am using the powers of Satan.
Light and Truth, that doesn't answer the question.

And Karl P, I'm not asking why they find it evil so don't throw bible quotes at me. I'm asking why they think it's from Satan when even Satan himself can't tell the future. So if Satan can't tell the future, how is he supposed to give this power to humans?
Lakers: well, considering I've heard many Christians telling people that psychic powers come from Satan...