Fresh reports of the McAfee update “felling PCs across the world” is sweeping across the news and help forums.
The problem seems to be a false-positive that surfaces when a new DAT file is patched on an older McAfee engine. The 4th of July holiday probably helped a bit too with people being a little less alert.
These things will happen, and the important lesson to learn is the critical focus required while working with security systems that have a costly false-positive impact. Hollywood has been cashing in on this idea for decades (remember Robocop?). These things will get more interesting as we move to security systems more sophisticated then these.