This commentary explores A Local Authority v A and B [2010] EWHC 978 (Fam), [2010] 2 FLR 1363 in which two cases were heard together. One involved a child and the other an adult, each of whom was locked into their respective room at night by their families for their own protection. The commentary explores whether the best interests test does - and should - work in a similar way when dealing with children and adults. It also explores, in more general terms, how the responsibilities of the State to protect people in these groups ought to be understood.