It is immoral to deflate a poor person's tires or put sugar in a gas tank. It is dangerous to dig a hole on a highway. Destroying large oil infrastructure does send a message if you make the news for a few days. However, if it raises gas prices significantly, it might just make more enemies.
If I were a domestic terrorist, I would damage luxury goods and services owned by people who invest large sums in oil. Hell, targeting luxury products and services could even be done non-violently. People just need to be creative and not target things that the everyday person uses. Luxuries aren't as big of a national security risk to governments, meaning the rich will have to invest more of their money into preventative measures.