At least five activists were arrested Tuesday for blocking a shipment of pipeline for Canada's much-hated TMX project by locking themselves to the dock in Vancouver WA where it was to be unloaded. The action by Portland Rising Tide was the third targeting the port for its role in transporting particularly heavy, dirty Alberta tar sands crude for a $7.4 billion project that environmentalists, First Nations, and many others view as a disaster in the making.