President Donald Trump says he will slap a 100% tax on movies made outside the United States — a vague directive aimed at protecting a business that America already dominates.

“Our movie making business has been stolen from the United States of America, by other Countries, just like stealing ‘candy from a baby.’ California, with its weak and incompetent Governor, has been particularly hard hit,” Trump posted on Truth Social on Monday morning. “Therefore, in order to solve this long time, never ending problem, I will be imposing a 100% Tariff on any and all movies that are made outside of the United States. Thank you for your attention to this matter.”

It was unclear how these tariffs would operate, since movies and TV shows can be transmitted digitally without going through ports. Also unclear is what it would mean for U.S. movies filmed on foreign locations — think James Bond and Jason Bourne — or what legal basis the president would claim for imposing the tariffs.

The president had first issued the threat back in May. He has yet to specify when the tariff might go into effect.

Movies are an odd battleground for a U.S. trade war. “Unlike any other country’s film industry, U.S. movies are the most accessible, well-known, and best performing due to the numerous language options and worldwide reach provided by U.S.-based studios,” trade analyst Jacob Jensen of the center-right American Action Forum wrote in a July commentary.