If I&#x27;m reading it correctly, a recent Microsoft study of Bing and Hotmail traffic showed 80% of users could be uniquely identified using passive, server-side fingerprinting of just client IP address and User-Agent header.<p><a href="http:&#x2F;&#x2F;research.microsoft.com&#x2F;pubs&#x2F;156901&#x2F;ndss2012.pdf" rel="nofollow">http:&#x2F;&#x2F;research.microsoft.com&#x2F;pubs&#x2F;156901&#x2F;ndss2012.pdf</a><p>&quot;User-agent
strings combined with IP addresses have an entropy
of 20.29 bits—higher than that of browser plug-ins,
screen resolution, timezone, and system fonts combined.&quot;