The US maker of the popular Firefox browser is offering a plug-in it says will allow users to monitor who is following their digital footprints. Mozilla says its Lightbeam extension, a free download, uncovers and displays which third-party companies are watching a user\'s online activity, including brands and advertisers looking to share users\' data or directly target them with ads, Mashable reported Friday. \"As a part of Lightbeam, we\'re creating a big-picture view of how tracking works on the Internet, and how third-party sites are connected to multiple other sites,\" Mozilla said in a statement. Interactive visualizations of such tracking in the form of graphs, clocks and lists will allow users to see this collected data to identify the sources of the tracking, it said. \"The visualization grows with every site you visit and every request made from your browser,\" Mozilla said in the statement. \"In addition to the graph view, you can also see your data in a clock view to examine connections over a 24-hour period or in a List view to drill down into individual sites.\" Users can download the Lightbeam extension at https://addons.mozilla.org.