Libertarians are sometimes quite principled folks who, though they may sin, at least have the decency not to reuire that you sin too. Real libertarians will also recognize the positive power of ostracism (shunning) as a substitute for busybody government. If we had a law requiring everyone to have fire insurance to pay a private fire company to put out fires, we might jail the homeowner who does not pay premiums. This is rather a drastic solution, particularly where that homeowner is ready, willing and able to pay for any services necessary to prevent his fire from burning your house. It is a lot less exp[ensive for all concerned to shun deadbeats than to jail them.
If a libertine would particpate in the discussion, he or she might ask for another joint (smokable not livable).