Daniel Davis, 18, from Osborne Road, London, was sentenced to 16 months along with Korie Hassan, 20, from WindsorRoad, Thornton Heath, Surrey and Hussein Abukah, 20, formerly of London.
Links between WindsorRoad and Ewart Drive in Newton Stewart, New Abbey Road to the Kirkpatrick Macmillan Bridge in Dumfries and Craigs Road to Georgetown in Dumfries have also gained support.