my two cents.
Of course there strikes can be reactionary (as Revol mentioned, strikes in defence of a loyalist state, anti-semitic strikes, anti-immigration strikes, strikes aimed at excluding women workers from the workplace). The question is, what do you do. What end do you want and what means to you use to obtain it? fFor instance, in the case of the anti-woman strike, do you want the employer to break the strike (so he can hire women workers at lower wages) or do you want to win male workers over to the idea that they should protect their own working conditions by acting in solidarity with women workers? For me it is the latter, which is why you stay on the picket lines, making arguments, and trying to change the field of struggle.
So as to the french rioters, as Raw Sllac pointed out, riots are chaotic events, made up of very different elements, good, bad, ugly, neither. But whose interests are served if the army go in and declare military law?Whose interests are served if there is massive repression. Not the interests of the community, but the interests of the state that has for so long abandoned the community. That is why you act in solidarity with the rioters (and not align your self with the state).
I don't think the bad should be ignored - the means do not justify the end - but we have to be mindful that a) the powers that be always present the half of the story that protects their interests - we do not know what is happening in the suburbs and speculation in a vaccum is particularily useless and b) the commiting of anti-social acts by rioters does not remove responsiblity from the french state.
The death of Jean-Jacques Le Chenadec was a tragedy in my view, I don't think we should ever belittle the loss of human life. But his widow said two things, the first addresses the men who killed her husband, the second the man who created the conditions which caused the riot
a) I want these people punished, I want people to react - that French people be conscious of all this. That a man died for nothing.
b) [Sarkozy] "lit the fuse with his provocative remarks, It is because of him that Jean-Jacques is dead."