Swings and Signs

I was strolling... er... wandering through a local park in Yakima. Everything seemed typical/normal. A slide, a swingset, the usual playground equipment in a park. But notice the yellow sign next to the swingset below? I wondered, what could that sign be for?
So I got a closer look:Why would adult supervision be required for a swingset?! I can see the reason for any child under 6years old, but this sign seems to include all children. I find this to be a joke. I grew within a half block of an elementary school. From the time I was 7 or 8 years old, I would go over to the playground there alone or with other kids from my neighborhood.

There are alot of good places for a sign like this... a beach for instance. But America's children have been using swingsets unsupervised for years. I can only remember one abnormal story related to a child and a swingset. ;)

Time to take a page from a friend's pseudonym and end my rant ;)