They could use the json.org license: https://www.tldrlegal.com/license/the-json-license

It's literally the MIT license with an added clause of only using the software for good, not evil.

Obviously, corporate attorneys will advise not to use the software since good and evil aren't really well defined legal terms. It's also not open source using the osi definition.

It's also unenforceable, therefore useless.