Lan presents a blog post revealing the Dark secrets of BERT. This work uses telling visualizations of self-attention patterns before and after fine-tuning to probe: what happens in the fine-tuned BERT? George brings a novel technique to the show, "radioactive data" - a marriage of data and steganography. This work from Facebook AI Research gives us the ability to know exactly who's been training models on our data. Kyle: Learning Important Features Through Propagating Activation Differences