I think it was Mark Twain who said, "Children should be kept in a box with air holes until they are 18 years of age." While I always chuckle at that tongue in cheek quote, one thing I most certainly don't approve of is putting children on leases. Now, I know what you're thinking: "What the hell does Nick know? He doesn't even have any kids!" Very true, but I do have 3 wonderful nephews and a niece, who are all very curious and active. True, sometimes I can't keep up with them, and I have to chase them, but I don't think putting them on a leash is the answer.
Besides, somehow the leash would end up comically wrapped around my neck and arms, or in a tree, or something along those lines.
The leash thing seems pretty extreme to me, but then there's the other end of the spectrum: Parents who are too busy texting or chatting to notice that their kids are about to fall down the stairs or run into traffic. A few years back I grabbed a little kid by the collar as he was about to run into traffic in Manhattan. The mother, who was on her cell phone and not paying attention thought I had just grabbed her son for now reason. The guy standing next to me explained to her that I had most likely just saved her son's life. She was a bit nicer to me after that.
Parents, you probably don't want parenting advice from a confirmed bachelor, but I'm offering it anyway-Keep and eye on your kids, and the leashes on the cats or dogs.