The Air Force gently introduced me to the concept of curfew back in 1977. Up until that point, I was young and naive, and the Air Force figured that establishing a curfew.....would ensure be the practical solution to ensure safety and limit property damage. We were told to be basically back in the tech school dorm by 11PM on school nights. Generally, I'd say that the curfew accomplished little to nothing....mostly because they didn't take names or do roll-call each evening to make it effective.
After that brief period in 1977.....other than a brief period in Panama where I saw curfew done (with no positive effect), and another during a TDY period to Incirlik, Turkey (also no positive effect).....I can generally say that curfews are a wasted effort.
Watching TV over the past two weeks from Missouri and this Ferguson episode....I'd generally say that no one really pays much attention to curfew rules. It doesn't matter if it's coming from the cops, the mayor, the city council, the governor, some military general, or from the President himself.
Years ago, I got into a discussion with someone who'd spent time in Detroit back in the early 70's when the riots occurred there. As a kid, they tended to notice three simple facts about riots, curfews and damages.
First, timing means everything. Folks like to riot between the late afternoon to around midnight. No one ever riots at 6AM or 9AM in the morning. Riots rarely ever occur in winter, but are extremely evident in summer. In Panama, I tended to notice protests to always occur after lunch, and usually ended by 4PM in the afternoon so everyone could get on the regular routine buses, and get home before the last bus run of the day. No one ever gets stirred up in morning hours....burning down business operations or breaking into stores to loot.
Second, somewhere in this mix of rioting....is booze or drugs. You don't usually hang out at a riot unless you've had a beer or two, or done a hit or two on weed.
Third, whatever the original intent of the riot or protest was about......it's usually forgotten as folks progress into a riot or looting episode. It's more about looting or getting your piece of the redistribution.....and no one remembers much of what got them upset in the first place.
Cops will tell you that in every community.....there is authority to establish a curfew. I generally challenge that attitude or law. A military commander does have such authority over his troops or his post. Beyond that.....it's hard to say that curfew is legal in any state or city. Arrested breaking curfew? I'd challenge anyone who says you could end up with jail-time. Basically, the cops just arrest you.....drag you to some downtown jail, and as the sun rises....release you. There might be a later court date.....but they lack any firm law that would really work and sustain itself in a legal setting.
I kinda noticed that various news journalists were out and about, during the curfew setting.....acting as though they were exempt from such rulings or orders. That kinda says something about how people interpret curfews.
A wasted effort? Well....if folks were really peppy about their subject.....they riot and loot from sun-up to sun-down. They rarely ever do that. So, it's mostly an effort to party, drink heavily, smoke some weed, and hangout with the crowd.....oh, and loot of course.