A stray blond hair, a wayward smudge of lipstick--these used to be the tell-tale signs of philandering, but even they permitted some deniability. Today's proof of adultery is likely to be encoded in a smartphone. Technology has made it easier than ever to uncover an affair, but adulterers have been slow to realize that sending text messages to the extramarital object of their affection isn't the best way to keep infidelity a secret. Just ask Tiger Woods (or Detroit Mayor Kwame Kilpatrick, or Senator John Ensign, none of whom seemed to get the message in time). Columnists lay out the new rules of the cheating game.

  • Text Messages Are Digital Lipstick on the Collar If you must cheat, The New York Times's Laura Holson says you should be aware that "Text messages are the new lipstick on the collar, the mislaid credit card bill." And they're hard to get rid of. "Instantaneous and seemingly casual, they can be confirmation of a clandestine affair, a record of the not-so-discreet who sometimes forget that everything digital leaves a footprint."
  • If You're Using Technology, You're Writing For Publication  Slate's William Saletan thought his readers should know. "Wise up, cheaters. Your passion for what's-her-name may be gone with the sunrise, but text is forever. Just because it has vanished from your screen doesn't mean it has ceased to exist, any more than your wife and kids cease to exist when you fly to Argentina."
  • Texting Can Be Used in a Court of Law  The Philadelphia Inquirer's John Timpane notes that scandalous text messages have helped send politicians like Detroit Mayor Kwame Kilpatrick to prison.
Last year, Kilpatrick, the Detroit mayor, got snarled in a sex scandal when a few of the thousands of messages sent between him and chief of staff Christine Beatty in 2002 and 2003 somehow landed in the lap of the Detroit Free Press.

'I've been dreaming all day about having you all to myself for three days,' he texted her. 'Relaxing, laughing, talking, sleeping and making love.' And apparently not bothered by the fact he'd sent these texts on a city-issued pager. Or that by city directive, messages via city media are 'not considered to be personal or private.' Political downfall, jail time, and fines ended his tale.

  • If Texting Doesn't Get You, 'Webtribution' Might  The Wall Street Journal's Elizabeth Bernstein reports that the web is making it easier than ever before to seek revenge on a cheating spouse. Berstein tells the story of Jacquelyn Eschbach, an editor in Philadelphia:

When she found out her husband was cheating on her last March, she logged onto his Facebook account, deleted all his privacy settings--allowing anyone to see his page--and created a new status update for him: 'Moving back to my mom's because my wife caught me cheating with a woman from work.'

  • Encrypt Your Phone  Atlantic correspondent Edward Tenner suggests beefing up the privacy settings on your phone. "The solution for some of the privacy activists I've met is to make strong encryption a norm. Until it is, those who encrypt messages might well be attracting the kind of government scrutiny to which they object so strongly -- what do they have to hide, anyway? But if almost everybody encrypts e-mail, text messages, and other information, the stigma is gone -- in domestic situations, too."
  • There Are Some Things You Shouldn't Need Technology To Tell You  Salon's Kate Harding breaks it down:

Let me give you a tip for free: If you're so convinced your partner is cheating on you that you're moved to indulge in technology-assisted snooping, unless you are living in a madcap romantic comedy, you are probably not going to learn that his strange behavior is part of an elaborate engagement plan and/or a plot to demonstrate how much you mean to him.