Lightbeam is a Firefox add-on that uses interactive visualizations to show you the first and third party sites you interact with on the Web. As you browse, Lightbeam reveals the full depth of the Web today, including parts that are not transparent to the average user.
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Basically when you visit a site that reconnects with a dozen other 3rd party sites Lightbeam shows them all in connected bubbles (and allows you to block them). So take Cracked.com, visiting that webpage also pushes connections to scorecardresearch, sharethrough, doubleclick, cloudflare, dmtracker, nr-data, bluekai, exelator, tru.am, krxd, moatads, newrelic, ricdn, sumome, couple google sites, and then all the social media sites.
MMX boards is almost it's own tiny little bubble, mostly interconnected through image hosts from user images and my google searches.