A valid point, but a lot of complications and unanswered questions.

One major problem is that it weakens the rule of law (something that most libertarians prize highly) when you throw so much into the courts. Nobody knows where they stand or what their liabilities are, which leads to paralysis.

I identify with libertarians, but I think it would be much better to come up with clear laws inidicating the costs of negative externalities, and then force various behaviors to pay for those costs in various ways to various people. Also, certain practices should be outright criminal, in the same way that vandalism is a crime.

I think things like cap-and-trade are ridiculous, for instance. But a straight tax on air pollution or drawing from the water table might be reasonable.