It looks like AOL just did something nasty. According to reports at Slashdot and reports here on LJ, AOL is blocking just about everything LiveJournal related. Many hosts (Geocities and Angle Fire, for instance) block linking images. This makes sense because the images–and the pages that are supposed to host them–are hosted for free by these services. They get income by forcing advertising on your pages. If you link an image directly, they have no ad, get no money, and have to pay for the bandwidth. This is reasonable.
AOL, on the other hand, has blocked EVERYTHING from LiveJournal. They blocked image linking (like many other sites), which is no big deal. The important thing is that they blocked normal linking, too! Basically, anything (a link, a picture, etc) from a page on www.livejournal.com to AOL gives a 404. Paste the same link into your browser directly, and you get the content. Strangely, their filters do not catch other subdomains (like a paid account domain like brienigma.livejournal.com).
People are saying this is a mistake and they probably meant to only block images. Other people are saying it is a conspiracy–LJ is the biggest web log site out there and AOL just launched their own (competing) web log service. Sparse reports also mention that email from @livejournal.com, like notifications, is also blocked. AOL supposedly installed a new spam filter today, too.
I urge anyone who still uses AOL to consider the alternatives–especially if you are still going to be using LiveJournal. There are numerous other ways of getting on the net out there.