It appears that Insanejournal is purging journals that have been inactive for 2 years or more. Some of these I haven't even looked at in so long. A couple were made for a game that started on Greatestjournal--or at least, I think so--which never made it over to Insanejournal after all. Just going by the fact there's a now long dead link to an RPG application, which was somewhere on Greatestjournal and is now lost in the void.
The last time I made a post under my own username over there looks to have been in August of 2010. Since I basically remain logged in with that one via Firefox and take a peek around every few months, it comes through without an inactivity notice.
In another one, I spotted that I had uploaded some user icons others had made from the first issue of the original team of Excalibur. So prior to the permanent deletion of that journal, I saved the icons, and uploaded them Dreamwidth. Nothing was there to be saved in the rest, and it's fine for them to join the list of the deleted.
If you're on the Dreamwidth side of the fence, you can see one of the icons I spared is being used for this post.