Urgent security notice: embedded content security breach. As far as known at this time, LJ has had a security breach with the embedded content domain lj-toys.com. This breach resets the icon and metadata of your most recent post and sets the security to public, along with inserting malicious Flash content into the body of the post, within minutes of viewing an infected Flash file. Then, other people viewing that Flash content in your entry will also become infected. Because of this, embedding on LJ has been disabled, so there should be no new infections from the LiveJournal site itself. However, many people are already infected.
Go read so you're sure you're safe.
My latest entry (before this one) was affected, so I've now deleted it just in case.