All the owner of that site has to do is put something that violate LiveJournal's Terms of Service on that page and report Owen's post to LJ Abuse. Unless Owen can prove by context that he originally posted to a non-objectionable site, his journal is now subject to sanction up to and including deletion. The burden of proof is on Owen. Note that content does not have to be unlawful to be a ToS violation, and even if it's unlawful in California or the U.S., it might not be unlawful where the server is hosted.
Bottom line: If someone on LiveJournal links to a site you control--OR HAS EVER LINKED THERE--you can get their account
I've been staying out of the various "sky is falling" nonsense w/r/t LJ/6A's apparently bad policies...but this policy shows how really, truly, deeply the new owners Don't Get It.
I'd sue them for making my "permanent" account valueless, but that's probably a violation of the ToS.