By which I mean strikes, work stoppages, etc. It seems than in times of high unemployment (such as the present) it would be easier for capitalists to hire scabs and to convince the state to bring in police. The New Deal was an aberration, of course, because FDR used the state to create employment and other social programs. It can be argued that he did this precisely because the frustration of the many unemployed people might have otherwise led to revolution. Though the economic situation is similar (worse in many ways considering the labor sector of the economy has been shrinking since the boom years of the 80's-90's and much of the natural "resources" have been used up), the political situation is very different now, keeping a liberal administration from swooping in to give hand-outs.
The answers to this question necessarily inform which tactics workers would be wise to adopt.
(I personally would rather see the factories abandoned, but I know many, including anarchists, aren't ready for such a radical move.)