Anarchists, ELF, Marxists, and Socialists. Take your pick, but one thing's for certain, they exist all right, but far-lefts are becoming more and more accepted in today's society as moderate-rights are being reprimanded for their rational views. It's also worth mentioning that Nazis aren't far right, but are just far up. They actually lean slightly to the left.
The far left has existed in numerous forms, such as the Soviets (die-hard Communists). In today's society, we have drifted so far left that I believe, we, as a society, are coerced into ignoring it, as if the far right have 'spoiled' our chances at pushing any further right than the leftists approve.
If your point was about loose left governments and strict right governments, then any primitive society in which we would deem anarchist today, could qualify.