In many markets, 20th-century TV stations ran PSAs right before the local evening news reminding parents that they should probably know where their children are. This 1979 gem from Grace Jones may be the best one.
Never mind that knowing where your children were was pretty much impossible unless someone near a landline had eyes on them. Over the years, they got a lot of folks to do them.
A very serious Debbie Allen:
And of course, Homer Simpson:
• Grace Jones–Do You Know Where Your Children Are?, 1979 TV (YouTube / Alan Eichler)