Holders of the Zero Aggression Principle.
The World's Smallest Political Quiz categorizes people along the dimensions of FreeDom of economic activity and freedom of personal activity (e.g. sex and drugs), creating quadrants for Conservat Ive (econ free, personal not-free), LiberAl (econ not-free, personal free), PopulIst/Authoritar Ian (not-free, not-free), and Libertarian (free, free).
KarlHess was a well-known LibertarIan.
Critiques of libertarianism http://world.std.com/~mhuben/libindex.html
Libertarianism makes you stupid: http://sethf.com/essays/major/libstupid.php
The Libertarian Party seems rather unpopular, even among LibertarIan-s.