I don't know, I usually consider myself something of a libertarian, yet I don't believe in "absolute and unrestricted liberty." It seems pretty clear that if one person has absolute and unrestricted liberty, he cannot avoid being able to encroach on someone else's absolute and unrestricted liberty.
F.A. Hayek, who is one of my inspirations, rejected, after consideration, the label of "libertarian." I'll have to look up why, later.
It "seems pretty clear," is the problem. If liberty is defined as being free to do whatever one chooses without interfering with anyone else's liberty, what you suggest is impossible. In fact, thus defined, every other relationship between individual means that someone is usurping authority over another individual's life. The correct name for that is tyranny.
Those are your choices, liberty or tyranny. Most people are petrified of liberty, because it also means they must be responsible for their own lives. Most people prefer tyranny.
Hank