The following are excerpts from NYS Article 22-A: Consumer Protection From Deceptive Acts and Practices.
General business laws are broadly similar in other states. They are relevant because most hospitals do not inform a patient when he arrives for voluntary treatment that he can be detained against his will. This can be viewed as deceptive business practices, if not false advertising.
§ 350-a. False advertising. 1. The term "false advertising" means
advertising, including labeling, of a commodity, or of the kind,
character, terms or conditions of any employment opportunity if such
advertising is misleading in a material respect. In determining whether
any advertising is misleading, there shall be taken into account (among
other things) not only representations made by statement, word, design,
device, sound or any combination thereof, but also the extent to which
the advertising fails to reveal facts material in the light of such
representations with respect to the commodity or employment to which the
advertising relates under the conditions prescribed in said
advertisement, or under such conditions as are customary or usual.
§ 350-d. Civil penalty. Any person, firm, corporation or association
or agent or employee thereof who engages in any of the acts or practices
stated in this article to be unlawful shall be liable to a civil penalty…
§ 349. Deceptive acts and practices unlawful. (a) Deceptive acts or
practices in the conduct of any business, trade or commerce or in the
furnishing of any service in this state are hereby declared unlawful….
(h) …any person who has been injured by reason of any violation of
this section may bring an action in his own name to enjoin such unlawful
act or practice, an action to recover his actual damages or fifty dollars,
whichever is greater, or both such actions.
The court may, in its discretion, increase the award of damages to an
amount not to exceed three times the actual damages up to one thousand
dollars, if the court finds the defendant willfully or knowingly
violated this section.