Phones are certainly a useful tool in helping to keep in contact so can be useful if you get into trouble. But they don’t always help because they don’t always keep us in contact. There are many reasons why a mobile may be useless. There may be no signal. Or the phone may have been turned off. Or the battery may have run low. If any of these things happen then it adds to parents worries as they can’t get in contact when they expected to be able to.