>Code by default is usable by anyone.
"by default". Any serious entrepreneur wouldn't fall on the default to begin with if the potential losses are that large.
> registry of copywritten code would appear which we could easily cross-reference.
Sounds like a good recipe for more Oracle vs Google battles in my eyes. We just have a reference on what NOT to write. Now there will be discretion on if you just happened to write this kind of code or if you took X+1 lines of a code base when X is allowed. Very useless metrics for a productive piece of software, but the kind thst will absolutely be used by courts.