From a purely laissez-faire perspective, so long as the union does not call for government interference -- and there is no indication in the article that they h

From a purely laissez-faire perspective, so long as the union does not call for government interference -- and there is no indication in the article that they have done so -- their strike action (or threat of such) is merely a way to influence the supply side in the question of supply and demand. Do you feel this to be illegitimate? If so, why?