It's up to the parents then to 'stamp' on it. If I were a parent with young children I'd certainly do that. They might not like it but as parents you sometimes have to take an extremely firm stance, in order to safeguard your children.
I didn't either until I saw a bit about it in the paper. Apparently you accept a challenge to do something stupid, and possibly dangerous involving alcohol, and then challenge someone else to do likewise.
GM, it's a craze on social networks - mostly kids film themselves drinking stupid amounts of alcohol, then dare others to do the same. People have died.