For this entry, I'm assuming that this is a feature, rather than a bug awaiting fixing.
The current FAQ reads:
There appears to be an abandoned journal. Can I have the username?
No, because LiveJournal does not delete accounts for inactivity.
Even though it may appear that a user is no longer updating their journal, this can be misleading; the user might be making Friends-Only posts, or simply use the account for reading friends' posts and commenting on them. Some users also find themselves without Internet access for prolonged periods of time, but will continue with their journal at a later date.
Additionally, usernames are not currently recyclable. Even if the journal were deleted, you wouldn't be able to claim the username. If your desired username is already taken, try a variant (such as adding numbers, extra letters, or underscores), or select another username entirely.
The last paragraph needs to be edited or removed. I'd suggest something like
"Only the person whose journal it is can decide to delete a journal. If a journal is deleted and purged, you can rename your journal to that username. Doing so requires a rename code. Renaming is explained in <http://www.livejournal.com/support/faqbrowse.bml?faqid=25>.
"If you do not want to pay to rename your journal, or if the username you want is unavailable, try a variant (such as adding numbers, extra letters, or underscores), or select another username entirely."
The last phrase is from the current version of the FAQ.