Most T&Cs don't mean anything anyway. There are no default T&Cs, there's just the law. Publishing code without a license doesn't give it an "implicit all-right

Most T&Cs don't mean anything anyway. There are no default T&Cs, there's just the law. Publishing code without a license doesn't give it an "implicit all-rights-reserved license" - it's just illegal to copy because that's what copyright law says. A license is a conditional waiver of copyright law, a contract where the author promises not to enforce copyright against you if you fulfil certain conditions. (and this is legally binding so they actually can't enforce copyright against you)