I was sitting near the fan who was "stealing" the signs and calling them out (he is not related to me). We were sitting behind the catcher and could see his signs openly. The fan in question actually told your coach that the catcher needed to keep his hand up rather than drop it down where it could be easily seen. Your coach started asking him after each of your defensive innings whether the catcher's hand was dropping. The catcher started hiding his signs more consistently.
I don't agree with calling out anything our from the sidelines, so I am in no way defending him, but I think it may have ended up helping your team. At least you knew that your signs were visable. If our fan had not said anything, the signs would have remained visable for all to see. By speaking up, he at least gave your coach a chance to stop the showing of your signs and may have prevented our coach from reading them.
At any rate, knowing what is coming at you and being able to hit it are two differnt things. I think your pitchers could have told our batters what they were going to throw and it may not have made much of a difference. You have a lot of talent and they were fun to watch.
Hopefully, the games this past Saturday will help your catcher remember to keep his hand tucked up during your conference game tomorrow and in future games and there will be no way his signs can be stolen. Good luck tomorrow!