It seems like one of those laws that is a "convenience law." I.e., it's there for the convenience of the police if they see something suspicious and want to question you, or something they can hit you with if they don't like your attitude.
That that simply to provide something to charge you with? If you are acting suspicious, surely they have the power to question you anyway curfew law or no curfew law?
That was poorly phrased. Let me see if I can do better.
Simply being out late is not sufficient reason to be stopped or questioned for most people. It gives them a reason to stop and question people who are out late and may be up to no good. If you look young enough that you might be out after curfew, that's reason enough for them to stop and ask you for identification.
Obviously, if they see you doing something illegal, they're going to stop you. But simply "being suspicious" can involve a wide range of things, and curfew laws give the police a reason to, at the very least, ask for identification if you look like you might be underage.
In general, I think these laws are intended to deter gang activity and what people might refer to as "anti-social behavior" elsewhere (petty crime, graffiti, etc). As a result, I'm betting they are more heavily enforced in inner city areas rather than in suburbs or rural areas.
Sure but that not the most useful aspect of this. If you are out past curfew and underage you've committed a crime. The police officer has a specific and arcticuble reason to perform a terry stop and search you. If they find something illegal on you that's a bonus but now you're trapped. Its an easy way to establish probable cause and gain compliance.
Even better is looking young and driving past curfew. Again this is the kind of thing officer will use for a PC stop. Sure you're 20 but the officer doesn't know than until you've been stopped and provided license, registration, and proof of insurance.
If they want to search you, they would need probable cause; simply "acting suspicious" isn't enough. Overly broad laws like this give them a convenient way of bypassing the 4th amendment.
That that simply to provide something to charge you with? If you are acting suspicious, surely they have the power to question you anyway curfew law or no curfew law?