According to a report from Ken Rosenthal and Evan Drellich of The Athletic, the Houston Astros used a video system to steal signs from pitchers in 2017. The report cites multiple sources including former Astros pitcher Mike Fiers who confirmed the use of video cameras and the banging of a trash can to signal if a pitcher was throwing a breaking ball. Internet sleuths have also found the game mentioned by former pitcher Danny Farquhar and it appears you can hear the trash can banging in question.
The Astros have released a statement that they are looking into the matter but have yet to formally comme on the matter.