Wow....you just took web analytics and tracking and somehow morphed it into the holocaust. That's probably the biggest slippery slope argument I've ever seen in my life.
But this nazi example is one everybody can relate to because we're all familiar with it. But if this is too strong we could go a bit further in history and talked about richelieu "If one would give me six lines written by the hand of the most honest man, I would find something in them to have him hanged." and the current state of us law [2].
[1]: http://americablog.com/2013/03/facebook-might-know-youre-gay... [2]: http://www.harveysilverglate.com/Books/ThreeFeloniesaDay.asp...