Workers striking against Tesla in Sweden have finally drawn a response from the company’s famously anti-union boss.

Musk said on X, the platform formerly known as Twitter that he owns, that the situation was insane.

Tesla CEO Elon Musk responded to news that Swedish postal workers are refusing to deliver Tesla license plates, joining a wave of action in sympathy with mechanics who stopped servicing Tesla cars late last month.

A group of 130 mechanics began their strike in October after their employer, a Tesla subsidiary in Sweden, refused to recognize their union.

Dockworkers began blocking Tesla car deliveries at the country’s ports, electricians stopped maintenance work for the company, and other workers in Sweden joined the strike, Expressen reported.

The original strike, called by Sweden’s IF Metall union, was about “good wages, good pensions, and good insurance” for its members.

The negotiations with Tesla have been ongoing for quite some time. The Swedish labor market violated basic principles after they refuse to sign collective agreements.

A majority of the country’s workforce is unionized, with around nine out of ten workers covered by collective bargaining agreements.

However, unionizing at Tesla has been difficult. There have been at least three attempts by its American workers to organize, mainly due to aggressive tactics employed by the company and weak labor protections.

Tesla and Musk have repeatedly been criticized by the National Labor Relations Board, a US federal agency, for illegal or improper anti-union activities, such as interrogating employees and disciplining or otherwise discriminating against workers.

Tesla’s employees in Germany, where it has a large plant manufacturing batteries and electric vehicles, may be emboldened by the strikes by Swedish workers.