Money being taken from my check

All of the people at my facility where I work have received a notice stat6ing that they overpaid people money when they worked doubletime since October 2006 and are now beginning to deduct that money from all of our checks. They stated that they will be deducting it in incriments of 50 dollars a paycheck. And that for people with large amounts will be working out payment arrangments with them.
Is it legal for them to take out the money without giving us previous warning? And if so is it legal for them to do so without showing us the discrepencies in our pay?
My opinion on this situation is that if they screwed this up since october of 2006 it either should have been caught sooner, or due to there neglegence been let go as a loss on their part due to there neglegence.
Thank you for any assistance given.

[annjd]

They need to notify you and give you a chance to dispute it.

They cannot just take it.

You may call your nearest Dept of Labor office if need be.