There seems to be a lot of confusion about this request. It is not asking that any user be required to show his distance unless he wants to show it. What it asks is for a way for User X to limit who sees his distance to other users whose distance he (User X) can see. It's reciprocal. It's saying "I don't want you to be able to see my distance unless I can see yours." It's actually a very reasonable feature request.
Brian
There seems to be a lot of confusion about this request. It is not asking that any user be required to show his distance unless he wants to show it. What it asks is for a way for User X to limit who sees his distance to other users whose distance he (User X) can see. It's reciprocal. It's saying "I don't want you to be able to see my distance unless I can see yours." It's actually a very reasonable feature request.