Lightbeam for Firefox gives users the opportunity to see and understand the types of tracking information that companies are able to gather about their visitors online. It enables you to see a graph of the people who are active on a particular webpage that you are visiting. When you visit another site, you will be able to see which users have used both sites and which ones have also seen you at both sites. You can continue to see this cumulative data with each new site that you visit. You also have the option to use the clock view to track it over the time of the course of a day.
Like many other sites online, Lightbeam does store your information, but it saves that information to your computer. You are free to delete it whenever you choose, as well as to disable the data collection by Lightbeam. The extension was created by Morzilla and Carr University of Art + Design as a means to enlighten internet users about the type of information that was gathered and stored by companies, as well as to inform them about how cookies work. It was inspired by then-Mozilla CEO Gary Kovacs, who wanted the public to become better informed about how they are tracked online.