It's possible to believe you're doing something right and still be acting against the rules.
Let's just imagine -- completely hypothetically, of course -- that I recently wrote a crawler specifically designed to rescue client websites from a terrible DIY website service (which might or might not be Jimdo). Let's imagine it was tuned to load Jimdo-related assets (or the assets of a similar service), fix broken code, etc.; I'm pretty sure this would have been against Jimdo's rules (or the rules of a related service, if I had done such a thing, which, surely, I did not), but let's say I did it anyway because I think it's reprehensible that they don't provide a way for their customers to export their websites.
It's possible that I could have found myself on the pointy end of an expensive lawsuit over something like this. It's possible that I would have broken some laws that I am unaware of, had I done that -- and, had I done that, it would only weaken my case further to claim foreknowledge of the laws being broken. It's likely that there are laws which could be loosely enough interpreted to make me guilty of some form of "hacking". (And it would be most certainly utterly stupid to even consider leaving a comment like this under my regular username -- if, of course, I had done such a thing. Fortunately, as HN occasionally reminds me, I'm not competent enough to have done something like this.)
But there's no way I'd ever say that I did something "wrong", and there's no way I would have asked for Jimdo's permission to do something like that. I simply knew what the rules were, and I believed it was the rules, not I, that were wrong.