EXPERIMENT: What People’s MetaData Gives Away. “We did not anticipate finding much evidence one way or the other, however, since the MetaPhone participant population is small, and participants only provide a few months of phone activity on average. We were wrong. We found that phone metadata is unambiguously sensitive, even in a small population and over a short time window. We were able to infer medical conditions, firearm ownership, and more, using solely phone metadata.”