You could have introduced yourself, struck up a conversation with them, asked if they were neighbors, where they lived, Andy Griffith style, maybe they were in need of a decent adult role model in their lives. But there is always next time. Told them you weren’t necessarily opposed to them fishing but the proper way to go about it is to ask permission.
Going on other people’s property without their permission is a red line for me, it’s definitely a no go with me, I blame their parents for not teaching this lesson.
Like I said earlier, I grew up in a farm community where you could get shot at if you were caught on another farmer’s property without their permission and gotten a beating when you got home.
Plus, in our neighborhood we have signs all over the place that say fishing is not allowed, why have rules when people ignore them.
We had another situation similar to this at the community pool where my wife and I own a condo, the sign at the pool says no children under 14 allowed without the parents supervision, one day a small group of owners were sitting by the pool when 3 children clearly under 14 came out to swim, one of the owners told them they couldn’t swim in the pool without their parents being there, the kids left and immediately their parents came down and were mad that someone told their children they couldn’t swim, when the owner pointed to the sign and the rules, the parents weren’t happy but had to accept their kids could not swim without their presence.