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.
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.