Embedded Identifiers
Color laser printers print a few tiny dots of yellow to help secret service to identify printers used to make counterfit money. One of your experts mentioned "finger printing" at the same time saying that it can be easily defeated. What might help is to embed the MAC address into certain tools that are being used to create distributed denial of service. When a legitimate app tool for checking security is used to attack, the attack would leave bits of information about the originating computer.
I read about producers putting microchips in their oil so that if a shipment gets highjacked that the microchips could be used to prove who has the rights to trade the oil. This is a bit behind the idea of imbedding unique information that can be use to find the source of control. The microchip idea works fairly well with lost pets, the hitch is the type of microchip, whether the animal is registered in the owners name and also if the shelters have the time to check the chips.
