It was meant to be a system that is meant to be extremely hard to crack, cards that were meant to be incredibly hard if not impossible to copy... yet all that took for them to be copied was a simple colour printer. The recently released PS3 exclusive The Eye of Judgment has been cracked wide open, and as mentioned they only used a colour printer.

They were have said to have used "special ink" that could be read by the eye, but it seems any and all cards can be read as long as they have the "special codings" correct on the card.... hmmm it seems that The Wizards of the Coast and Sony should thoroughly test these things before releasing them....

...But to their defence, I understand that they never thought to use a Colour Printer to test the "copiability" of the cards.