Every cuecat scan results in some garbage that looks like the following:
Hidden inside that code is the barcode type, and its numeric or alphanumeric equivilent. But there's more: There's also a serial number. And that serial number is probably easily matched up to the store where you picked up your cuecat device, or even to your name if you gave it to the clerk at the store. If you got your CueCat in the mail directly from Digital Convergence, chances are that serial number is already in a database somewhere along with your name. If you got it with a magazine, there's a pretty good chance that information is kept about which ranges of serial numbers were sent along with which magazines and to which areas - if not a direct cuecat serial number to subscriber corelation.
(Some people claim that you identity would not be revealed by CueCats purchased at Radio Shack unless you filled out the forms presented by the CueCat installation process because all CueCat packages have the same barcode. However there is still a strong probability that your identity could be determined from Radio Shack sales records if you started scanning barcodes on things you recently bought at Radio Shack.)
000000000215756002 UPA 691839000011
The first item in the second line is the serial number. Then the barcode, and then the numeric value of the UPC type A code. This serial number stuff is real bad news. It's like a cookie that can't be turned off, and it gets sent to Digital Convergence every time you scan a barcode that brings you to a web site using their software.
Of course, they're going to be pissed about people using their barcode scanners without their spying software: They want to make money by seling your personal information. They know where you live. They know what books you read, and they know what products you buy, all by what you scan with their little cuespy.
The cease and desist letter they've sent is a vague piece of crap. Its sole intent is to intimidate. They have no legal standing. First spying, now intimidation tactics? I think perhaps it's time for a TLO to investigate Digitial Convergence.