The labor movement of the late 18th century can be described in this way because the biggest strikes that the unions were involved in tended to be aimed at the biggest companies. These were the companies that were run by the "robber barons."
One famous example of this was the Homestead Strike of 1892. In this episode, the labor union struck against the Carnegie Steel Company. This company was owned by Andrew Carnegie, one of the most famous of the robber barons. The union was trying to prevent a series of major wage cuts that the company was trying to impose.
Strikes like these can be characterized as involving rebels and robber barons. The companies were owned by the rich robber barons. The strikers were rebels because they were trying to fight back against the traditional way of things in which workers complied with what their bosses demanded of them.