Yeah, looking at those buckets, the water inside is prolly heavier than the kids who would be able to fit head first inside them.
Not only that, but the diameter looks big enough to allow a kid's shoulders and arms to fit inside, but not big enough for any kind of motion once there.
I'll either get some of those buckets, or some kids, but not both. Frankly, this is really starting to trouble me. I'm with Airhead, and I will do my part by writing to my local omnibudsman to legislate against these dangers.
Sandman, I'll trade ya my balcony for your yard.