That’s the basic idea behind the IWW, but because of their tremendous success with that tactic early in the 20th century, laws were passed that made it illegal

That’s the basic idea behind the IWW, but because of their tremendous success with that tactic early in the 20th century, laws were passed that made it illegal to strike in solidarity with workers in another workplace. It still happens, (for instance there was a lot of that kind of activity in the recent teachers strikes) but it is illegal. Ironically it’s basically illegal because it works.