It's been reported that Cleveland is the team that alerted the Sox to this issue.
Cleveland was also on to this guy.
& yes! DD did in fact deal with the issue early on in Game 1 ALCS.
It would stand to reason that this is a coordinated effort by the ASTROS organization to steal signs. Now, don't get me wrong! I'm not at all shocked by this! Every team does this at some level. This of course explains why neither the Sox or Cleveland have made a big deal about this. Nobody really wants to get too outraged about it, as that would simply bring light on what they all do.
For me, it's just fun to point out that they all do it, & stick it up the arsses of those who are constantly calling the PATS "cheaters." These guys who are constantly going off about this with the PATS are either incredibly stupid, hopelessly naive, or complete idiots. Most likely all 3.