For years, retailers have been told that if they merely abide by common sense security procedures--don't permit obvious passwords, check audit logs regularly and patch software immediately--they'd be in good security shape.

Although there is no doubt that is still sound counsel, security consultants are describing <A HREF="http://www.eweek.com/article2/0,1895,2113835,00.asp?kc=EWWKDEMNL041307EOAD">a new breed of professional cyber thieves</A> out there, crooks who know as much about sophisticated forensic investigations as the good guys do.

An oversimplification would be to compare the old thieves to burglars who make serious attempts to be very quiet when breaking into a house and to leave as little evidence as possible. The new thieves care less about quiet entrances because they intend to meticulously clean the crime scene before they leave. They're not just covering their tracks--they're erasing them.