It is important for kids to be physically active, and play individual or team sport(s) if they choose. What is the line between "sport" and "extreme sport", and if your child showed a preference for an "extreme sport", would you let them participate?
For instance, if you think about safety, would you allow your child play: tennis, baseball/softball, basketball, BMX bike racing, snowboarding, kid's motorcycle racing, football, ballet, chess (just kidding)...
Sports injuries are likely to occur, and the injuries sustained from extreme sports are usually more serious (especially if no protective gear is worn) than compared to the "traditional" sports. The injuries from "traditional" sports are typically found to be related to repetitive-motion or environment ("heat stress", for example).