Crocs Inc., the makers of those infamous perforated plastic clogs, announced Friday that 18 Chinese counterfeiters were sentenced to more than 46 years in prison for selling 128,752 pairs of knockoffs. More than $9.6 million worth of shoes were confiscated by officials. “If you attempt to produce or sell infringing Crocs products, we are going to find you,” warns Dan Hart, chief legal and administrative officer.