Obviously everyone points to his critiques of leftists/liberals, but I think it's more worth noting his theory of disruption of the "power process". It's basically just a description of Marx's theory on alienation. The only thing that I disagree with him on is that the problem isn't industrialized society in general but the capitalist mode of production. Instead of a revolution to regress society to primitive-communism, progressing it to socialism and then communism would be a more efficient way to deal with the problems of alienation we face today.