In Brookfield, Wis., no restaurant has triggered more calls to the police department since last year than Chuck E. Cheese's.

Officers have been called to break up 12 fights, some of them physical, at the child-oriented pizza parlor since January 2007. The biggest melee broke out in April, when an uninvited adult disrupted a child's birthday party. Seven officers arrived and found as many as 40 people knocking over chairs and yelling in front of the restaurant's music stage, where a robotic singing chicken and the chain's namesake...