McAfee anti virus runs wild, removes good filesThis hasn't happened to MC, but it's a good example of the harm that other software sometimes does
http://www.theregister.co.uk/2006/03/14/mcafee_av_false_positive/Excerpt:
"A faulty signature update from McAfee flagged up legitimate application files as infected with a low-risk virus, CTX. The dodgy anti-virus update (4715 DAT), issued on Friday, March 10, falsely identified a number of component files of Microsoft Office applications and some Windows systems files as infectious. Along with Microsoft Excel, components of Adobe Update Manager, Macromedia Flash Player and Google Toolbar were falsely labeled as viral. McAfee has produced a seven page list of files known to trigger incorrect identification."