More well-known to whom? Most non-technical people I know have never heard of Linus Torvalds, or Linux. Kevin Mitnick is a name that has been in the media in much more prominent positions. As far as the "hacking" vs "cracking" debate, that fight has been lost for many years.

You really think non-technical people actually know the name Kevin Mitnick? I'm a 'technical person' and this is the first I've ever heard of him.

Again, anecdotal evidence on my part suggests that he's more widely known than Linus Torvalds. I have no solid data to back that up.