The One and Only

In the case of matter duplication, there are very few minute differences between the original and the duplicated object. However, to help prevent counterfeiting and other deception, some replicators have built-in mechanisms for marking objects they create. One such mechanism is the replication tag; usually only visible at the molecular level, this tag does not alter the form of the replicated object, but marks the object as replicated and not created through conventional craftsmanship.
After only a short time, the mark s that merely signify replication give way to marks that designate individual ownership. These "anti-theft" tags lead to criminals seeking to master the secrets of the molecular marks. Using techniques such as kidnapping, blackmail, or extortion, devious amoral masterminds circumvent the anti-counterfeiting and anti-theft mechanisms. Of course, the time and resources required mean that such circumvention is used only for the most important or expensive of items.
The next step in matter duplication advances the identity mark to a tracking mark that sends out specially coded transmissions indicating the item's location. Once again, this "foolproof" system enjoys only a brief sojourn of primacy before it, too, is foiled by the determined villain.