Backups of xwiki wikis?

Hi there, I have already asked this question some time back but I didn't get a definitive answer and I'm getting a bit worried: Are the xwiki wikis on xwiki.org (for example mavenbook.xwiki.org) backupped? If so how often? Thanks a lot -Vincent PS: I've also tried the script that Jeremi gave me and it seems there's an error somewhere in it. I'll contact Jeremi.