It doesn't make sense? How so? They are supporting the strike by boycotting Tesla.

Stealing or withholding property is not a legitimate form of striking. If you don't want to deliver something, fine, but you can't stop someone from picking it up themselves

They are not stealing or withholding the property - they are refusing to deliver it. They are not stopping someone from picking it up, postnord is. It would be weird for any carrier to allow outsiders to enter their premises.

There are two defendants: postnord and the state agency.

Postnord should not refuse to let Tesla collect the plates that Postnord has. That would be theft

How is it theft? Nobody is touching the plates.

Welcome to Sweden, where unions and corporations determine the rules, and the government tries to stay out of it.

Which is actually a great system in my opinion. However, the government does still have to step in if the parties break law.

Just going by what's been reported, so let me clarify I'm totally ignorant of the actual facts of Swedish law. But it appears that Tesla can't pick the plates up due to a law on the books stating that plates must be sent via mail.

I'm using the word "picket line" informally to describe a strike / labor action, which I would guess is a legally protected and regulated thing in Sweden, as indeed in the US.