The oil came out of the Earth in the first place. I won't gratuitously pour it in a hole or storm drain, but cart around a kit? Hell no. It's got to stop somewhere.
I never understand the "oil came out of the Earth" argument.
Yes, crude oil came out of the earth. But then it was refined and run through a vehicle where it picked up a ton of contaminants. What leaked out of a truck is very different than what came out of the ground.
Also, when was the last time any of us was walking through the forest and came across a patch of "natural" oil just sitting there? Short of living somewhere where natural tar pits occur this just doesn't happen. Oil forms underground, not on the surface. It takes a very small amount of a petroleum product to pollute a large quantity of water.
I strong agree with the "take out what you brought in" and "leave it the same or better than you found it" philosophies when it comes to nature. There is no way to prevent oil spills, accidents can always happen, and it does not take much gear to be able to handle one. At the minimum you need a plastic bag and some paper towels, which everybody probably has already.
- Matt