【案例】张光明等人均是某科学研究院的保安,但他们却先后与几家不同的劳务公司签订过劳动合同。面对频繁更换的劳务派遣公司,虽然用工单位承担连带责任,但劳动者的权利也很难得到保障。 [Case] ​​Zhang Guangming and others are security guards of a scientific institute, but they have successively signed labor contracts with several different labor service companies. Faced with frequent replacement of labor dispatch companies, although the employing units bear the joint responsibility, but the rights of workers is also difficult to be guaranteed.