(b) Unless otherwise provided by law, where a peace officer has lawfully entered the premises, the peace officer may seize any alcoholic beverage in plain view that is in the possession of, or provided to, a person under 21 years of age at social gatherings, when those gatherings are open to the public, 10 or more persons under 21 years of age are participating, persons under 21 years of age are consuming alcoholic beverages, and there is no supervision of the social gathering by a parent or guardian of one or more of the participants.

Where a peace officer has seized alcoholic beverages pursuant to this subdivision, the officer may destroy any alcoholic beverage contained in an opened container and in the possession of, or provided to, a person under 21 years of age, and, with respect to alcoholic beverages in unopened containers, the officer shall impound those beverages for a period not to exceed seven working days pending a request for the release of those beverages by a person 21 years of age or older who is the lawful owner or resident of the property upon which the alcoholic beverages were seized. If no one requests release of the seized alcoholic beverages within that period, those beverages may be destroyed.