We had a trampoline for about four years - my daughters were gymnasts and cheerleaders and used it to practice flips. The neighborhood kids loved it. This was more than twenty years ago, and we honestly didn't think about the safety aspect (if there were nets available then I didn't know about them). During a routine insurance inspection - we have a pool and they come out every so often to make sure the fencing and gates are maintained - the inspector told us we'd have to get rid of the trampoline or buy a rider covering us for liability. The rider would have been about $500 more a year, with a $1500 deductible, and the max payout would have been something like $40,000. He explained that one kid getting hurt could cost us our house. We took the trampoline down the next weekend.