Leashes on your children?

Angie
I thought of these things a beyond ridiculous idea every single time I saw parents put their little ones on a "leash".
Today when I was scrolling through Facebook I saw a terrifying video of a little girl getting yanked out of a store in an attempted kidnapping. I know a lot of people who didn't see the video would say "keep a better eye on your kids" or "that's just bad parenting". 
Honestly though the little girl was not even 2 feet away. In fact her mom was looking right at her because the little girl was pointing something out when the guy just busted through the door and grabbed her by the arm. The mom was also holding her baby. 
I couldn't help but think the whole time: "those leashes don't seem like such a bad idea in busy areas where things like this could happen in broad daylight at the drop of a dime." 
I feel kinda ignorant for judging those parents that have used these leashes. It's like there's a stigma on them for some reason but in reality they could provide additional safety it seems. 
I mean, I'm not a mom myself so I can't argue with people's parenting choices but I was just curious as to how some of you guys felt about this?