http://it.slashdot.org/it/06/03/13/1322215.shtml
Woopsie!
[Friday] McAfee released an anti-virus update that contained an anomaly in the DAT file that caused many important files to be deleted from affected systems. At my company, tens of thousands of files were deleted from dozens of servers and around 2000 user machines. Affected applications included MS Office, and products from IBM (Rational), GreenHills, MS Office, Ansys, Adobe, Autocad, Hyperion, Win MPM, MS Shared, MapInfo, Macromedia, MySQL, CA, Cold Fusion, ATI, FTP Voyager, Visual Studio, PTC, ADS, FEMAP, STAT, Rational.Apparently the DAT file targeted mostly, if not exclusively, DLLs and EXE files."
Woopsie!