When someone gets an abortion, they may decide not to share information with friends and family members. But chances are their smartphone knows. The leak of a Supreme Court draft opinion proposing to overturn Roe v. Wade raises a data privacy flash point: If abortion becomes criminal in some states, might a person’s data trail be treated as evidence? There is precedent for it, and privacy advocates say data collection could become a major liability for people seeking abortions in secret. Phones can record communications, search histories, body health data and other information. Just Tuesday, there was new evidence that...