I'm writing an article about blocking DidTheyReadIt web bug spy ware.
I sent my wife a message through their service (free trial, 10 messages at no cost), and if she loads the external images in the email, I get all sorts of interesting information about when, where, how, and for how long she read the message (and it's pretty decent too).
They do this with a web bug 1x1 image. Now I am curious what happens if people all over the world load this image:
I'm figuring that the system must be pretty dumb, and won't figure out that it isn't really here in 200 countries at the same time (although they seem to forget that I could read mail just as easily through a connection in Europe as I can from my home internet connection).
If you load that image, I might get to see the user-agent string of your browser, the referer URL, if any, the best guess at your nearest upstream provider, your IP address as far as the first NAT gateway, when you loaded the image, and the Accept header of your browser. However, because of the hashing, it will look to me like my wife is doing the reading.
So, if you are brave enough, help me screw up their data.