If you live in New York and have left your home since the middle of March - a safe bet unless your governorship ended then - you’ve seen messages everywhere. Harsh little missives scribbled in black on a white background. On bus stops and taxis, billboards and buildings. They’re everywhere. And they’ve blanketed Los Angeles and Chicago, Dallas and San Francisco, too. The petty taunts of a scorned lover.

“My Mother Always Hated You, Sarah Marshall.”

“You Do Look Fat in Those Jeans, Sarah Marshall.”

“I’m SO Over you, Sarah Marshall.”

“Wow!,” you think. “Someone really pissed off her boyfriend and, hoo boy, he is NOT shy about airing their dirty laundry! The claws have come out!! Also: he must have remarkable reserves of disposable income and a great deal of free time. Hey, wait . . . I have disposable income! Just about eleven dollars and fifty cents. I wonder if there’s an easy way to spend it, quickly and mechanically . . .”

Of course, that isn’t what happens. Among the sentient, or at least among those young, gorgeously media savvy who got wise when they got born, “mysterious messages” mean only one thing: a bit of viral marketing. I’ve seen cryptic things plastered on bus stops and subway stations. They don’t carry trademarks or even directions to a Web presence.