"Investigators believe Cardinals officials, 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 who had joined the Astros when they worked for the Cardinals. The Cardinals officials are believed to have used those passwords to gain access to the Astros’ network, law enforcement officials said."
"Believing that the Astros’ network had been compromised by a rogue hacker, Major League Baseball notified the F.B.I., and the authorities in Houston opened an investigation. Agents soon found that the Astros’ network had been entered from a computer at a home that some Cardinals officials had lived in. The agents then turned their attention to the team’s front office."
"Investigators believe Cardinals officials, 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 who had joined the Astros when they worked for the Cardinals. The Cardinals officials are believed to have used those passwords to gain access to the Astros’ network, law enforcement officials said."