I think strait jackets are cruel too because being restricted at the best of times is going to turn on the temper tantrums either way, but if it stops the harming then its a solution. But I would be more inclined to go for a strait jacket then a caged bed. A padded room however I feel would be the better option - but then who am I to dictate..... I really admire JK though, she is no fence sitter!