The whole hacking term is subjective. Everyone interprets it how they want, without any relation to the true and original meaning. Having that said and having in mind that Hacking in short is questioning the technology, I say yes - hacking is very much legal. Hacking can become illegal when you break and do things that are against the law. In example breaking into your own computer/network is OK, because it's yours. Doing the same thing to someone else would be illegal. See where's I'm getting at?
Your terminology is flawed and I'm sick of explaining this to every one of you people!
