Agreed, but as the guy from Russia in this thread said, the NSO is very popular! Not to mention that 50-70,000 people is a VERY strong following. 70,000 is 1/2000th of that population number you gave me. If every 1/2000 people was a skinhead, in a Moscow croud there could be hundreds.
Also, the government isn't really cracking down on them. They arrest those who are outspoken about their acts, or those who they catch attacking people, but with this kind of following, just taking down the leader won't end the conflict.