[andy58-in-nh]

Here is the difference:
Someone else's exercise of "liberty" can, at the extreme, cause physical harm to others or render their property uninhabitable. Human behavior does not occur in a vacuum - that's why we have laws and government to enforce them. The fact that we've gone far beyond the proper limits of law and government (and we have) does not mean that law and government are unneeded. Negative third party effects of human action (such as noise, pollution or narcotics distribution) are best dealt with by the police power of a government under clear standards of fault and liability - but they still must be dealt with.

[mvpel]

I don't think you'll find any libertarian who will say that polluters or anyone else should be immune from liability for the harm they do to others.

That's what the courts are for, and it's only the anarchists who say we don't need a government-run court system. Most libertarians aren't anarchists, though.

With respect to narcotics distribution, yeah, I know what you mean... the local CVS has had a really significant negative impact on traffic in the area, and our taxes have to pay for the maintenance signal that went in at the entrance to its parking lot.