The national police are worried about a well armed internal enemy; organized crime. The police estimate that 500 major businesses are controlled by 116 criminal gangs. Some 4,000 hard core criminals operate these gangs, and use illegal methods (extortion, murder, tax evasion) to deal with business problems. There are also 140 youth gangs, with about 5,000 members, that act as sort of a farm system for the adult gangs. These criminal groups are often used by terrorists to obtain weapons, and other services needed to carry out terrorist attacks.