Request user consent for placing 'tracking cookies'. As of the 26th of May 2012, all EU citizens visiting your website(s) must provide their explicit consent to allow 'non-essential' cookies. Very simply put, the visitors need to be made aware of the cookies the visited website uses. This impacts many (if not most) websites, but certainly those using third-party cookies like those from Facebook, Twitter, Google (Plus, Analytics, etc), Webtrends, Omniture and many, many more.
In comes Konsent. A free and open source (MIT/GPL dual licensed) 'cookie consent' library, fully written in JavaScript. Konsent will let you determine the users consent and handle tracking accordingly.
Read more on http://konfirm.net/konsent