Sir, Sunday's rally against the Keystone XL pipeline ("U.S. protest paints Keystone as emissions villain" 17 February 2013) shows the huge constituency allied against this destructive project. Toronto 350.org was there because Canada and the U.S. must work together to build the infrastructure that will let us transition away from fossil fuels, not pipelines that will lock in decades more of unsustainable emissions from the world's dirtiest oil. Milan Ilnyckyj President, Toronto 350.org Milan Ilnyckyj Massey College 4 Devonshire Place Toronto, Ontario M5S 2E5 Cell: (416)715-4252 Email: president@toronto350.org letters@globeandmail.com.