A growing number of states are instituting “social host” laws, which are designed to cut down on underage drinking, The Wall Street Journal reports. The laws impose criminal or civil penalties on hosts who permit underage drinking on their property. As of January, 28 states had adopted such laws, up from 18 in 2005. Hosts can be charged regardless of who supplies the alcohol, or whether anyone is hurt, the article notes.

Several states, including California, have passed laws that impose penalties if someone is harmed by underage drinking. In addition, many counties and cities are passing their own social hosting measures.

Law enforcement officials across the nation say many teenagers find access to alcohol at house parties. Studies have shown that these parties are often where teens first start binge drinking. The social host laws allow police to arrest the host, without establishing who supplied the alcohol—which can be difficult to prove.

Mothers Against Drunk Driving supports social host laws. Opponents of the laws object that they can punish hosts who try to prevent underage drinking. The laws assume hosts know there was drinking in their home, or should have known.