

You didn’t break the law, just violated a contract. The user you gave your credentials to violated the law, because the contract you signed stipulated that permission for them to access your account was not yours to give. That means they accessed your account in an unauthorized manner, which meets the definition of hacking.
I am not trying to argue the merits of what does and doesn’t constitute hacking, but these terms have objective, legal definitions in the jurisdictions they’re taking place. We don’t have to like or agree with those things, but it doesn’t change the current situation that has them set up this way.








That maybe a philosophy held by some, such as to say walking into a house with a door swinging open should not count as trespassing, but I don’t know of anywhere where the law is set up that way, though I’m not very familiar with the laws in a ton of countries. Where I live, though, going somewhere uninvited counts as trespassing regardless of how many or few barriers there are to it. So, if you parachute into a secured vault with razorwire all around it with no trespassing signs everywhere, that’s the same crime as stepping in someone’s lawn that with a sign that says “please keep off the grass”.
I think the part that you’re finding galling is that many of us have a notion of hacking as as using a varied set of skills that are difficult to master towards bypassing complex security to gain access to locations or data. This contrasts greatly with the legal definition of that word, which can include those things, but really is so broad as to include going anywhere you weren’t supposed to with a computer. I imagine technical people especially might feel like calling someone that just logged in with someone else’s account information a hacker is insulting to the practice of hacking, but the legal system, at least in my country (USA) does just that.