If you read the post it says:
"There are plently of people on the left
as well as the right who, in the face of their inability to get others to agree with them through discussion and peaceful argument, are quite willng to use violence to get their way. Just like the National Socialist German Workers Party." (emphasis added)
However, the NSDAP tactics were quite similar to the Bolshevik practice of politics (Hitler very much admired the show trials), and the state that Hitler built had much in common with the USSR (including an alliance for the division of Poland). Roehm's brownshirts would feel very much at home in the black bloc.
As far as NSDAP ideology and political stance, it was actually a curious mix of classic reactionary elements that resonated with the old ruling classes (anti-deomcratic, anti-semitic, nationalist), while also being quite corporatist, statist, and revolutionary in the sense of overturning the old social order and creating something extremely new based on principles that grew out of 19th/20th century European thought (social Darwinism, eugenics, collectivism - see "Triumph of the Will" for a cinematographic vision of same). The NSDAP program also had some quite anti-capitalist elements, such as the following points from the "25 point program" - the official party platform
http://en.wikipedia.org/wiki/National_Socialist_Program make clear.
10. The first obligation of every citizen must be to work both spiritually and physically. The activity of individuals is not to counteract the interests of the universality, but must have its result within the framework of the whole for the benefit of all Consequently we demand:
11. Abolition of unearned (work and labour) incomes. Breaking of rent-slavery.
12. In consideration of the monstrous sacrifice in property and blood that each war demands of the people personal enrichment through a war must be designated as a crime against the people. Therefore we demand the total confiscation of all war profits.
13. We demand the nationalisation of all (previous) associated industries (trusts).
14. We demand a division of profits of all heavy industries.
These kinds of demands don't square with a simplistic view of Nazis as "right wing". And remember that Benito Mussolini was a revolutionary socialist before he was a fascist. Both communism and fascism have the same origins and share many of the same impulses, though they are not the same. Both came out of a twisting of Enlightenment philosophy on the relationship between man and the state. One branch of that discourse led to constitutional democracy (out of which came democratic socialism). The other branch, its antithesis in a suitably ironic Hegelian turn of events, was the totalitarian impulse which manifested itself in the last century as fascism and socialism/communism. While as political forces, both 20th century monsters are spent (though not completely extinguished), the underlying totalitarian impulse is alive and well. And mutating.