From the Washington Post:

Recess is dangerous. There’s all that name-calling, roughhousing and bullying. And the fast running! Why a child might trip, fall, even — and perhaps more important — sue.

Given such perils, Willett Elementary School, south of Boston, has cracked down on tag and other “chasing games.” Pia Durkin, the district superintendent, told the Sun Chronicle in Attleboro, Mass., that children’s energies should be better directed toward “good, sound, supervised play.” 

So they’ll be prepared for good, sound, supervised lives.