While I do not know any script kiddies, I have encountered leetspeak enough on EFnet and such places to provide a better definition of this term.
Usually, the term 0wn is used to refer to the computer that the script kiddie has cracked, or the (legal) owner of said box.
0wning a computer may involve having root/r00t on a Linux system, or having installed a trojan horse program such as Back Orifice on a Windows system. More likely, of course, the script kiddie did not himself (most are male) crack the system, but rather portscanned a large number of IP addresses searching for one with his favored trojan already installed.
Since many systems run operating systems or add-on software that logs connections to the default port of each major trojan horse, the script kiddie is very likely to be caught and lose his Internet account, or even be arrested if the would-be victim feels strongly enough about the matter.