While one may disagree with both their message and their tactics, they are either peaceful or violent. If they do no physical harm to other people, they are peaceful.

Frankly, I think they would have more impact if they took personal action to reduce demand for oil. The oil market doesn't have a lot of capacity buffer. If even 5% of the population stopped driving for every little thing, the Bakken oil fields would lose money hand over fist and be shut down. 

As a side benefit, global oil prices would plummet which would severely harm Russia, Iran, ISIS and Saudi Arabia, none of whom are exactly positive players on the world stage. I find it shameful that so many Americans continue to support those oppressive regimes with their driving addictions.