Microsoft's Terms of Use states that "Microsoft does not claim ownership of your Prompts, Creations, or any other content you provide, post, input, or submit to the Image Generator."

Midjourney's Terms of Service states: "If You are not a Paid Member, You don’t own the Assets You create. Instead, Midjourney grants You a license to the Assets under the Creative Commons Noncommercial 4.0 Attribution International License."