Modern oil pipelines have check valves and automatic shut-off mechanisms.

Even if a terrorist blows a hole in a working pipeline, only the anount of oil between between valves can escape, and pumps are automatically turned off.

Emergency alerts go out by radio to repair crews who are dispatched almost immediatley.

As Bert said, the proposed pipeline is the safest way possible.

If we (US) don't allow this oil to come here, the Canadians will be forced to construct a very expensive, destructive and dangerous line to the West Coast, and the oill wil go to China.