> in a perfect world labor unions would be illegal
As in workers can't legally demand higher wages as a group, as in those negotiations won't be legally binding and fines would be imposed on strikers, no need to hit anyone.
> fines would be imposed on strikers
.. which won't be paid, and you have to deal with the picket line.
State fines for non-attendance at work? State fines for calling in sick? Seriously, this is how you get Chile. Or Venezuela.
A striking union would be fined, they can figure out the allocation amongst themselves.
.. or not pay it.
And how are fines enforced? Does a libertarian really need to be educated on why their ideology came up with the NAP?
Laborers can't collectivize as soon as capital can't collectivize (incorporate). I'm on board this train, let's do it. Ban collective action in the economy, especially that supported and enabled by the government. In all its forms. Where's the petition I can sign?