Interestingly I was discussing this with some friends last night (trying to solve the worlds problems on the back of a napkin as always :) One suggestion was to

Interestingly I was discussing this with some friends last night (trying to solve the worlds problems on the back of a napkin as always :) One suggestion was to try and crowdsource deliveries in cities, ie. have depots centralised around public transport areas. But how to deal with security?