While looking for info on the coal mining practice of using canaries to detect carbon monoxide, I happened across an interesting term: canary trap. It doesn’t seem to relate to the coal industry, rather it seems to have originated either in a Tom Clancy novel, or actually among intelligence circles. A site on the topic offers the following explanation:

A canary trap is a counterintelligence technique that is used for exposing spies. Suppose you have four people in positions of trust, and you think one is betraying you. You entrust each with secret information, but you give each a unique version of the information. If the information later shows up in the possession of the enemy, you know who to put on trial for treason.

They advocate using this technique to identify spammers, and companies/websites who sell your personal data to other sources. Basically, the idea is each site you sign up for, you give slightly different personal information to. For example, you’d include the line “Department 1″ under your name (or else just use a different name). That way, when you get information addressed that way, you can know who ratted you out.

While this seems like a rather time-consuming process to enact some sort of weird revenge on spammers, it seems like sort of a cool idea just in terms of information distribution, and tracking how different channels transmit it.