I sort of like this. I wonder if it is enforceable.

"For my friends everything, for my enemies the law" software license.

> I wonder if it is enforceable.

I can't imagine that it wouldn't be. If a company has explicit written permission from the copyright owner granting permission to use that copyright, then they can use it.

Also, it wouldn't be a special license. If you wanted to do a "For my friends everything, for my enemies the law" thing, you'd just set it as all rights reserved and add special note encouraging people to ask for permission to use it.

Plus, copyright enforcement typically goes in the other direction. It's not about who you can sue, it's about who you can't. Licenses are just a way of specifying who you cannot sue. If you want everybody to use your project but don't want to bother with a license, you can make it all rights reserved (the legal default) and just not sue anybody. You could sue them if you wanted to (which is why nobody would ever use your code: because of the risk that you change your mind and sue them), but nobody is forcing you to.