But "scab" referred to people who replace striking workers, who acted to undermine organized struggles. It also sometimes referred to official and unofficial thugs (police, military, private for hire groups like the Pinkertons, umpaid volunteer thugs like the American Legion who were violent strikebreakers). In spite of Jack London's use of the word in a broader context it normally did not apply to people who worked more cheaply than norm or worked harder than the norm in the absence of such struggle. For that matter Martin Eden was explicitly asked by fellow workers not to work so hard. So even there, he acted against calls for solidarity from an informal organization. Why is it scabbing to work for free if it advances your personal self-interest in the absence of an organized movement asking you to do otherwise?
^^^^^ CB: For sure. It probably is not the best to call these workers for free "scabs". However, it might be a good idea to educate them on the history of strikebreaking in anticipation of future revival of the labor movement. In the course of that, hurting their feelings a little to prick their conscience and consciousness might be necessary.
Kind of like a "class consciousness shot in the arm". There will be no union organizing movement if the new generation of workers is left to consciousness of only their personal self-interest. There's a bit of a chicken-egg issue: which comes first the organizing movement or the consciousness of the workers ?