"We need to institutionalize people in order to prevent them from hurting themselves" has the same memetic-superweapon structure as "We need to torture terrorists to get them to tell us where they've hidden the suitcase nuke." The scenario as stated obviously has consequentialist merit (death is worse than prison, megadeaths are worse than torture), so you'd have to be some kind of huge asshole—or a former suspected terrorist—to say, "I claim that this hypothetical scenario is not realized nearly as often as you seem to be implying and therefore falsifiably predict that many of your alleged real-world examples will fall apart on further examination."