If you’re a user of QuickBooks on the Mac, you need to check out these two posts over at TUAW…
Apparently, if you run an updater to QuickBooks, that may or may not have been released by Intuit, all the files and folders on your desktop may be erased.
In addition to the fixes mentioned on TUAW, you could also use an application like Little Snitch to block QuickBooks from connecting to the internet.