Bolsheviks in Czarist Russia weren't anti-authoritarians, they were just preferred a different authority than was established.
No, libertarianism/minarchism/anarchism are real belief systems.
> If you prefer your own authority, does that make you an authoritarian?
If you prefer your authority be imposed on others, yes; dictators are very much authoritarians.
Bolsheviks in Czarist Russia weren't anti-authoritarians, they were just preferred a different authority than was established.