I know, I know a couple of them. I just don't understand them. Why cross that line? Why risk jail, your career, a whole pile of hardship? The real life consequences is what I'm wondering about, it's as if there is some kind of disconnect there between action and subsequent consequences.
If it is only because it is 'unlikely that you're ever going to get caught' then that's a gamblers argument. (I don't understand gamblers either, so that might be an explanation right there.)
I think part of it is age, maybe. Or rather life-experience, if you will.
I remember back in my early 20s what always stopped me was basic paranoia about getting caught. But that's just how I'm wired personally (and I was probably slightly irrational about the odds). I love breaking, bending and toying with the rules, but too chicken to pull through if it involved anything more serious than a silly prank on friends.
Nowadays (mid-30s), the first thing that stops me is a much more solid sense of what's right and wrong. I prefer it that way, because unlike fear of getting caught, it's a much more solid foundation to depend on.
If you have a hard time believing anyone would do something like this, look at the 1990s: we got a book practically every year about one hacking group or another breaking into phone switches, credit reporting agencies, government and military networks, and financial institutions. If you can do it, and you're unlikely to get caught --- and you are very unlikely to ever get caught --- why not? Plenty of smart people did stuff like this. Plenty of them.
The most interesting stories from that era did not get written up. Kevin Mitnick didn't write the TCP sequencer. Kevin Mitnick couldn't sequence an ordered array of integers if it was #defined for him in advance.