In response to our campaign, Facebook announced that it would open up its Ad Archive API next month. Read Mozilla's statement about the response here...

We are writing you today as a group of technologists, human rights defenders, academics, journalists and Facebook users who are deeply concerned about the validity of Facebook’s promises to protect European users from targeted disinformation campaigns during the European Parliamentary elections. You have promised European lawmakers and users that you will increase the transparency of political advertising on the platform to prevent abuse during the elections...

Actions speak louder than words. That’s why you must take action to meaningfully deliver on the commitments made to the EU institutions notably the increased transparency that you’ve promised...

Specifically, we ask that you implement the following measures by 1 April 2019 to give developers sufficient lead time to create transparency tools in advance of the elections:

• Roll out a functional, open Ad Archive API that enables advanced research and development of tools that analyse political ads served to Facebook users in the EU.
• Ensure that all political advertisements are clearly distinguished from other content and are accompanied by key targeting criteria such as sponsor identity and amount spent on the platform in all EU countries.
• Cease harassment of good faith researchers who are building tools to provide greater transparency into the advertising on your platform.