The foundation has also discovered that enabling Do Not Track doesn't protect users against the surveillance, since the data is being shared in the site's referrer header. In essence, the referrer header is a fundamental part of how the internet works, and can't be anonymized. That's why it's a little unnerving to see a string displaying a person's vital statistics in a format that's very easy to read. In the EFF's example (pictured), this URL was sent to Google's advertising service, DoubleClick, and shows that the user is a 40-year-old smoker living in Arizona and with an annual income of $35,000.

[Credit: The Electronic Frontier Foundation]

According to the AP, the White House has already responded to complaints, saying that the data sharing was intended to improve the customer experience for the site. It added that firms weren't able to collect this data to "further their own business interests." Given that last night's State of the Union covered a presidential pledge to protect the data of US citizens, it looks as if President Obama has some work to do in his own back yard.