The Houston Astros were stealing signs through electronic means in 2017, per a report at the Athletic from Ken Rosenthal and Evan Drellich. Mike Fiers, who was with the Astros from 2015-17, went on the record to confirm that the Astros were stealing signs at home using a video camera in center field that fed the catcher’s signs to a TV set up in the tunnel behind the dugout, while other sources who are unnamed also confirmed the information.
Fiers departed from the Astros after 2017, and Rosenthal and Drellich indicate that they cannot confirm whether that system, or something similar, was in place the past couple of years.