As Facebook noted at the time, one of the issues with detection systems is that there isn't much material to work with to create one and to act as a benchmark for testing. That project is also using paid actors to create a larger dataset.
Google and Alphabet's Jigsaw are contributing a dataset of 3,000 manipulated videos with 28 actors to the new FaceForensics benchmark, which aims to become an automated benchmark for facial-manipulation detection.
This benchmark is being developed by researchers at Technical University of Munich and the University Federico II of Naples. Google calls its videos the Deep Fake Detection Dataset. Details about the FaceForensics benchmark can be accessed on the researchers' GitHub page.