Mozilla is concerned about Facebook's lack of transparency regarding political advertising, Chief Operating Officer Denelle Dixon said last week in a letter to the European Commission. Mozilla is currently working to launch its Firefox Election package for the European Union Parliament Elections and says it is not able to provide EU residents with the desired transparency, mainly due to challenges encountered with their Ad Analysis for Facebook add-on. The add-on, Dixon explains, analyzes a user's Facebook feed to identify ads and how the user is being targeted, and informs the user on that. The data is also compared to information from public sources, to show differences in ads served to specific users. "These two pieces of functionality are critical to bringing greater transparency to political advertising and to advertising in general. However, recent c...