Ahead of the EU parliamentary elections, Facebook released an ad archive API, to allow independent researchers and journalists surface what was to make political advertising on the platform more transparent. However, the makers of Firefox said that while a preliminary review of the API determined it wasn’t up to snuff, time revealed how borked it was.
"Once our technical experts began working with the API we quickly concluded it was unusable", a spokesMozilla said.
Targeting information was not available, bulk data access was not offered, and the data wasn’t tagged properly. No search was alike. Repeating an identical search would produce wildly differing results. The state of the API made it nearly impossible to extract the data needed for researchers and journalists to “analyse ads” as Facebook had claimed.
It took the entire month of April to figure out ways to work within or rather, around, the API to collect some information about the political ads running on the Facebook platform. All of this was documented through dozens of bug reports provided to Facebook, identifying ways the API needed to be fixed.
Through that work, we were left with detailed documentation of every time the API failed, and every roadblock encountered and had developed a series of tips and tricks to help others trying to use the API.
For example, Facebook said the Ad Library application programming interface (API) allows you to perform customised keyword searches of ads. However, Mozilla found software errors crippled a user's ability to do keyword searches.
Facebook claimed that you could search data for all active and inactive ads about social issues, elections or politics, but Mozilla found technical or data issues affected a user's ability to reliably retrieve data from multiple searches.
Design limitations prevented users from retrieving a sufficient quantity of data, even if the API had been functional. It took Mozilla a a month to figure out how to use the API.
The API delivered incomplete data on most days from its release through May 16, when Facebook fixed one critical bug. But the API was broken again from May 18 through May 26, the last day of the elections.