Ok, so I didn't read through every single response in this thread so forgive me if this has been stated already...
"Leashes" for children aren't meant to be cruel. They serve multiple purposes. Added protection is one, it makes it more difficult for someone to *bleep* your child while you're say, bending down to pick up your wallet you accidentally dropped. They prevent your child from wandering too far away and/or getting lost in a crowd.
Trying to keep up with a young, curious, adventurous (or rebellious) child while you're attempting to get say, grocery shopping done, isn't always the easiest of tasks whether your child listens well or not. Children get curious and often lose focus (or simply forget), therefore they wander off and/or want to go investigate a toy or candy machine, something of the like.
Using said "leashes" for children has nothing to do with being lazy. There are also parents, grandparents, other relatives, or guardians that simply cannot keep the same quick pace as a young child.
My last point is this: Have you ever dealt with a young child who has any form of autism? I have. We used a form of "leash" when she was young for all of my previous points. With a child like this, (who at the time we hadn't any idea of what exactly was wrong & why things were the way they were with her [attention issues, understanding/comprehension, ability to listen & do as told, etc.] and the fact that multiple doctors hadn't any clue what was wrong either) not only is it extremely difficult for the parents/relatives/etc. but also for the child. Does this make me a bad person? Does this mean we're lazy? No, it doesn't. This "leash" did a great deal of good of for all of us. So don't trash talk something (or people) just because you don't fully understand it (or them). There is nothing wrong with using a "leash" for your children, so long as it's being used properly. If you had been in my situation, all you nay-sayers would certainly be singing a different tune. Just sayin'.
Hear Hear! Children are different. Not all children are little angels that always listen to you, no matter how good of a parent you are. And it isn't called the "Terrible Two's" for no reason! I have a cousin that has two little boys.... One always obeyed her and would always listen, the other was a rebellious little stinker that loved to run away cackling his head off as she gave chase. She normally wouldn't use a leash, even with the wild one, but if they went to anyplace crowded (eg the zoo, amusement park, state fair, etc.) she'd give her boys their backpacks just as an added precaution. There are other threats to think about besides kidnapping: a child could try to reach up to see what going on, and accidentally place their hands on a hot grill; or injured by some type of machinery (like the gears of some amusement ride); or just plain getting lost in a crowd and becoming panicked when they can no longer find their parents. Every year when we go to the state fair, I keep hearing announcements like "Would the parents of such-and-such please meet their child at the Dairy Pavilion Information Booth"
In fact my mother has said that looking back, she'd think of using a backpack with me and my sister. My parents were not lazy nor did they not know how to put up boundaries; if anything they were very good, loving parents, better than the parents of some of my classmates. We were normally well behaved, but every once in a while, we'd get lost in her momentary distraction. That didn't mean that my mom didn't parent well. And neither my sister nor I grew up using drugs, having sex as a teen, or otherwise being wild, uncontrolled people. We just tended to be curious and, not knowing better, would sometimes let our feet do the thinking.
One day we were shopping at the mall, and my mom and stopped to look at the price on something. When she turned back around, my sister had taken off and was nowhere to be seen. After a few minutes of frantic searching and calling out for her, there was that dreaded announcement to pick up my sister at the Godiva Chocolate shop (I guess as we had passed by, my sister saw the "candy shop" and wanted to go back and look (read as "eat") the chocolate for sale there). When we finally got to the Godiva shop, the clerk looked horrified to see my mom come to claim my sister. The clerk reported that a man in a tan, leather jacket had come in, knew my sister by name, and my sister willingly left the shop with him. Being that dad was away on business, my mom thought she had lost my sister forever to some stranger. The clerk was just about to call store security when our family friend re-entered the shop with my sister in tow. I guess he had been right outside the shop when he heard the announcement, so he thought he'd rescue her before she got into any more mischief.
It's like the guy that got arrested for duct taping his kid to the wall in the garage... The father was doing some wood-working in the garage that day, and the little boy (who idolized his dad) wanted to watch what Dad was doing. Because the dad was going to be using a lot of sharp tools, saws, etc., the father decided to use the duct tape to allow his kid to watch without getting too close to the tools and getting injured. A neighbor walking by saw the kid taped to the wall and called social services for child abuse. Except that the only time in this whole incident when the child felt scared or hurt was when the cops showed up and hauled his dad to jail. I think the case was eventually dismissed because the judge found that the parent, although unconventional, used some type of restraint to keep the child from harm, and that such restraints (like a play-pen, cradle, stroller, or a leash) are not abusive if used properly and under the parent's supervision.