I think anyone who owns a trampoline, or is thinking about buying one, should go to this site
www.tortslaw.com/trampoline.htm just to get an idea of who might be gunning for you if someone is hurt, and what some consider to be the standard of care that an owner might be held to!
I also will add that my DH saw, himself alone, 155 tamp injuries last year, and EVERY parent professed to have all of the safety rules for usage listed!! It was always the ONLY time the children had broken them.
70% of the injuries involved damage to the growth plates, which means long term orthopedic damage.
Most were involving more than one user, but not all. If there was more than one child, it was almost always the younger who was injured.
There were two deaths in the same time period. One was a 30something INSTRUCTOR who landed incorrectly.
Way back when, Ralph Nader wrote a book entitled "Unsafe at Any Speed" I think, with a little change of wording, it can be applied in this instance..."Unsafe Under any Circumstances."
BTW...my mother raised 5 children without seat belts, child seats, helmets, and placed all of us on our stomach to sleep. She didn't know any better, but we all survived, by the grace of God. Many children did not. I, and anyone reading this thread, now "know better" (or should) as concerns trampolines.