This is the label attached to the back of Riddell helmets:

WARNING: NO HELMET CAN PREVENT SERIOUS HEAD OR NECK INJURIES A PLAYER MIGHT RECEIVE WHILE PARTICIPATING IN FOOTBALL. Do not use this helmet to butt, ram or spear an opposing player. This is in violation of the football rules and such use can result in severe head or neck injuries, paralysis or death to you and possible injury to your opponent. Contact in football may result in CONCUSSION-BRAIN INJURY which no helmet can prevent. Symptoms include: loss of consciousness or memory, dizziness, headache, nausea or confusion. If you have symptoms, immediately stop playing and report them to your coach, trainer and parents. Do not return to a game or practice until all symptoms are gone and you have received medical clearance. Ignoring this warning may lead to another and more serious or fatal brain injury.

Any questions, John Fourcade?