I worked for a company that made a device back in the day. Many engineers had been issued one well before it was announced so that they could develop the software. Each device was carefully labeled with a sticker identifying whose device it was.

A picture of one showed up on a blog as a leak. The leaker had sensibly put a black box over the sticker.

The thing that neither the leaker nor any of the rest of us knew was that each device also had a series of bumps on the top and bottom of the device which uniquely identified it just as effectively as the sticker. He was fired instantly.

In fact the sticker was probably there as a red herring, to give false confidence to the leaker that he had countered the fingerprinting!

I wonder if dazzle patterns[1] on pre-release Xbox Ones had a similar function. If each pattern was unique, you could only hide it by obfuscating most of the device.

[1] http://uk.businessinsider.com/microsoft-xbox-one-leaked-to-a...

>If you have the chance to download documents from multiple accounts and IPs, then you can check if the documents are the same bit-for-bit.

Now imagine fingerprinting is done on the fly by your corporate proxy server.