Fortunately, that strategy does not work for HIPAA protected health information. Any identifying number or information fragment that allows you to connect back to the original patient is not allowed. In small communities, this can be as little as age, diagnosis, and zip code.
I expect some interesting court cases over this.
I've written a little Android app that updates a webpage with your location. I've thought that people with an expensive sports car might like to use it by leaving it in their glove box when their car is serviced, and seeing if the garage takes it on a "Ferris Bueller" style jaunt around town.
Your MAC address isn't visible outside your local subnet. Slashdot has no way of knowing your MAC address. (Unless perhaps you're using IPv6 without privacy extensions enabled, but I'm guessing Slashdot is years away from IPv6.)
And it's Slashdotted.
And how do you know where anonymous money has come from?
Make sure your code does nothing gracefully.