Very easy time if it's about commercial use (well, at least outside of china). Companies need to have licenses for the software they use, they have to obey copyright laws and trademarks, have contracts and permissions for anything they use in their day to day work. It's the same reason why no serious company wants to even touch any competitor's leaked source code when it appears online.

Just because AI tech bros live in a bubble of their own, thinking they can just take and repurpose anything they need, doesn't mean it should be like that - for the most case it isn't and in this case, the law just hasn't caught up with the tech yet.

It'd be dead easy, actually. Don't even have to actually ban it: For image generating models, every artist whose work is included in the training data becomes entitled to 5 cents per image in the training data every time a model generates an image, so an artist with 20 works in the model is entitled to a dollar per generated image. Companies offering image generating neural networks would near instantly incur such huge liabilities that it simply wouldn't be worth it anymore. Same thing could apply to text and voice generating models, just per word instead of per image.