Data cards appear to take on some sort of additional NBT tag or some other element when placed in a player inventory versus when they are crafted. This makes supplying them with LogisticsPipes difficult, as automatically-crafted cards will run through the system WITHOUT acquiring the tags, cards put in a supplier pipe will have been in the player's inventory and WILL have acquired the tag, and LogisticsPipes will not use one to supply a demand for the other. This may affect other inventory-management or logistics systems that discriminate based on NBT information.

Was able to reliably reproduce the change. Having a data card in the player's hand and right-clicking it will cause ALL data cards in the player inventory to change NBTs.

There may be other conditions during which this may appear, will continue testing.

Update: It is apparently possible to move data cards in and out of the player inventory without altering their metadata, but I am unable to do this reliably or determine the conditions which causes one or the other thing to happen.

NBT is added when the card is used. Before that it isn't suppose to be.. Can you verify this?

Cannot reproduce. All cards remain docile and unchanged until put into something that adds data to them, such as an Extension pipe.