With the legal system of the U.S. based on common law, motivations for lawsuits can range from legitimate legal grounds to cases filed with the intent of shaping case law to favor the socio-political aims of special interest groups. Clubs around the country have personnel and clientele that are purported to engage in not only sex acts on the premises, but also drug use and other criminalized activities. Incidents of such activity vary widely. Their prevalence is dependent on regional differences in the attitudes of management, entertainers, customers, and law enforcement. Strip clubs are obligated to enforce age limits for entry to the clubs and consumption of alcohol. If a club is found to have served a person under the age of 21 alcohol it can have its liquor license suspended or rescinded for repeated violations. Licenses can also be lost due to evidence of drug use in the club. Club owners have closed their businesses as a result of losing a liquor license.