Passwords

Investigators believe that Cardinals personnel, concerned that Mr. Luhnow had taken their idea and proprietary baseball information to the Astros, examined a master list of passwords used by Mr. Luhnow and the other officials when they worked for the Cardinals. The Cardinals employees are believed to have used those passwords to gain access to the Astros’ network, law enforcement officials said.

Cardinals Investigated for Hacking Into Astro’s Database – New York Times