This will be my last post, as I need to move on and get some work done today.
First off, I am calm. This happened on Sunday. I created this thread on Thursday. I do not have veins popping out of my forehead. I simply posted this thread to get advice about whether I should (A) Talk to the kids and parents about them not running through my backyard anymore or (B) Do nothing, and hope the situation does not get out of hand or becomes a liability. I was given some great advice from both people who agree and disagree with me, and I decided to let it go for now. If/when the situation gets out of hand, I will deal with it then.
Quite a few of you would be totally okay with having some stranger's kids playing in your backyard. That's fine. But do not assume that everyone feels that way, or should feel that way, just because you do. We all have different things that bother us. For example, the woman across the canal appears to hate birds. She chases the beautiful wildlife (Herons, Egrets, Ibises, etc) off of her property and will occasionally
turn the hose on birds flying over the canal in front of her house. Do I agree with her? No. But if I marched there, knocked on her door, and said all kinds of rude things to her, do you think I'd change her views? Of course not! And it's not going to work with total strangers on a message board either, so why be anything but civil to each other?
I grew up in an area where everyone had a fenced in backyard, so people you didn't know were unable to access your yard if they were not invited. So this foreign concept of people being in our yard without our permission is nothing other than trespassing to us. We also didn't park our cars on the lawn either, which is

....but I digress. And FYI - Just because it's something you're used to seeing, does
not mean it's right. I'm used to seeing people litter on the highways, but does that mean it's right? Bottom line, it's our backyard, and we don't want people there uninvited, We are COMPLETELY in our right to feel that way.
One more thing I wanted to address - I don't hate kids. I made it quite clear early on that our main concern was the liability factor. We don't want someone's child to trip and fall on our property, and then end up with a lawsuit. Sure, we are also upset simply because they came into our yard without permission, but it's not a kid thing. We'd be just as upset, if not more, if it were an adult. If I knew these children and they asked to be there, then we wouldn't have a problem. But somehow people have turned this into me being a horrible person who is "off her rocker" that hates children. That is a very unfair assumption to make of a total stranger on the internet, and I really don't appreciate it.
It's pointless to continue going back and forth on this. I want to enjoy the day and the weekend, and I hope you all do the same. Enough of the negativity.