You are talking nonsense.

B::DeObfuscate works on any perl code, whether run through Perl-Obfus or not. It has already been pointed out that it would work fine on other code. It's a generic deobfuscator, not specific to Perl-Obfus. You may as well try and declare perltidy and B::Deparse illegal.

The legality of running it on a piece of code depends on the licence for that code. If I wished I could purchase Perl-Obus, run it on a piece of my code, and release the "obfuscated" code under the GPL. It would be perfectly legal for people to do whatever they like to the source.

If I wished I could write a piece of code, release it with a restrictive licence and if somebody altered so much as a single tab they would be breaking the law.

Contracts, licences, patents and copyright control the legality of altering code. Obfuscation is a foolish method of trying to control source code.

If I'm going to obey the law whether the code is obfuscated or not makes no difference - I'm not going to fiddle with the source.

If I'm going to break the law obfuscation is so trivially overcome it's not going to make a difference.

If you're capable of making a living distributing your obfusticator - good luck to you. Just don't expect the rest of the world to agree with you.