If they backed up over the previous backup (meaning on the same tape or hard disk) the , there really isn't much you can do.

It is *theoretically* possible to read past the current data, but it's incredibly complex and time consuming, you have to look at minute differences in the flux of the magnetic media -- you're talking FBI-level forensics and a lot of painstaking manual work -- and that would probably be in the tens of thousands of dollars, if it were even possible.

Is there any possibility there's another backup of the database containing the blog entries anywhere else, like maybe a script that backs it up locally on the server?