I know what you mean, but I think they were originally intended as an indication to the Emergency Services in case of an accident, which has meant more than once that Fire crews have searched surrounding ditches and fields for a little one being thrown from an accident when there wasn't one in...
Younger people who never take the earphones out of their ears because they can't bear to be without "my music".
- Particularly when pushing buggies or prams and it would be more interesting and stimulating for the little person they are with if they actually spoke to them, smiled at them...