[hnbad]

They're kinda illegal in Germany, actually. Based on a legal change in 2017, employers are prohibited from hiring temp workers[0] to take over work from striking employees. There are probably loopholes by having excess temp workers on staff at all times rather than hiring them specifically during a strike but this kind of redundancy is probably frowned upon by shareholders more than the lost productivity of a strike.

[0]: Specifically the law addresses "loan workers" but Germany has fairly strict laws surrounding so-called "independent contractors" in these roles: https://www.buzer.de/s1.htm?g=A%C3%9CG&a=11