See Who’s Tracking Your Web History with Lightbeam for Firefox
Nothing is sacred on the internet. You already know that. You know that every click, every page view, is being monitored by somebody. But by whom?
Lightbeam, a free add-on for Firefox, shines a light on all the activity happening behind the scenes regarding your privacy—or lack of it. For each page you visit, the app uses visualizations combined with statistics to see all of the background processes that are present and collecting information. You get a real-time view of the recent sites you’ve visited and all the third-party sites that may be tracking or collecting data, with useful icons to distinguish between visited sites, third-party sites, cookies, and so on. There are a few different interfaces for viewing data, so you can stick to a simple list or use the more fancy clock and graph views. And if you want to offer up even more of your data and contribute to Lightbeam’s cause, they are collecting user-data to study tracking and third-party connections.
Some say ignorance is bliss, but if you disagree, try Lightbeam.