"I can also tell you — I don't really care, I don't know anybody over there — the Colorado Rockies were doing the exact same thing in 2018, and we caught them," said [the former catcher], who didn't articulate if that was during the regular season or postseason, but he intimated that the revelation played into Colorado's offensive struggles during that series.
"We played them in the playoffs. You know how many runs they scored in a three-game playoff series in 2018? Not many people watch the NLDS. They scored two runs in the ninth inning of Game 2 (actually Game 1). And they used to take a Theragun and bang it on their metal bench. They were doing the exact same thing from the TV. So, there you go.
For what it's worth, here's a thread accusing some specific teams and players of sign stealing and other forms of cheating.