If you can use it for research/purpose purposes, you just do, and if you manage to build something good enough, you can get funding to train your own model then.

Also, with business there are few "can do / can't do" - it's about managing risks. If a penalty for doing is negligible (FB cannot catch you abusing license in private), from a business standpoint there is no issue in doing so - especially with things that are ethically kind-of-ok.