Legal basis for suing a company that uses another company’s product/creations without approval seems like a fairly pretty straightforward intellectual property issue.

Legal basis for increased taxes on revenue from AI or automation in general could be created in the same way that any tax is created: through legislation. Income tax didn’t exist before, now it does. Tax breaks for mortgage interest didn’t use it exist, now it does. Levying higher taxes on companies that rely heavily on automated systems and creating a UBI out of the revenue might not exist right now, but it can, if the right people are voted in to pass the right laws.