As always, I use tagged addresses for websites. A couple of months ago, I noticed that lj-addr1@mydomain had started getting spam-- not a lot, but a little bit. When that happened, I changed it to lj-addr2@mydomain. As of December 27, that second address is getting spammed.
This mail is not going through LiveJournal itself-- it's going straight to the unique email address that I have on my LJ account. That address has never been used for anything but LiveJournal.