David Petraeus might not have been a good enough spy to avoid getting busted in the arms of his biographer, but he did use a damn clever trick for sneaky correspondence: the neglected draft folder.

So simple. So obvious, even. Maybe you've used it yourself—though it certainly didn't occur to me in yesterday's roundup of 21st century cheating techniques. The AP reports the spy master didn't even send emails to Broadwell—they just let them sit:

Petraeus and Broadwell apparently used a trick, known to terrorists and teen-agers alike, to conceal their email traffic, one of the law enforcement officials said.

Rather than transmitting emails to the other's inbox, they composed at least some messages and instead of transmitting them, left them in a draft folder or in an electronic "dropbox," the official said. Then the other person could log onto the same account and read the draft emails there. This avoids creating an email trail that is easier to trace.

Smart! Not smart enough, clearly, but smart. I'm not sure how the AP qualifies this as a "terrorist" tactic, but it's definitely a good one: email headers and other incriminating online bread crumbs are avoided with a shared dropbox. Though I wonder, is the "dropbox" the AP refers to actually... Dropbox? Semi-sordid as this all is, it'll be fun to see what other cheater's tricks this scandal turns up. [AP via WaPo]