Call it The Dorothy Scam. A reader of mine fell victim to it a couple of weeks ago, on one of those unseasonably hot September Saturdays. It's a reminder that pickpockets can strike, anywhere, in any fashion.

My reader got burned while riding a Metrobus along F Street NW between 13th and 14th streets. He was sitting about three-quarters of the way back, in a window seat, when a young man got on at 13th Street and sat down beside him.

The bus had just started pulling away from the curb when the young man suddenly leaned across my reader and shouted out the window:

"Dorothy! Dorothy! Wait right there, Dorothy!"

"Naturally, I turned to look out the window when he did that," my reader said. "I didn't see anybody respond, but I didn't think anything of it. Maybe I just hadn't noticed."

That's not all our man hadn't noticed. Dorothy's friend got off at 14th Street -- and so did my reader's wallet, containing $75 and all the identification he owned in the world.

A pickpocket had struck in the space of 30 seconds. That much was reality. Was Dorothy fantasy? "I have revised my opinion as to whether there ever was a Dorothy," said the victim, wryly.

Metropolitan police robbery squad detectives warn that crowded buses are among the most popular "operating rooms" for pickpockets. Men should carry their wallets in a pants pocket if they are sitting down, detectives say. Because the "Dorothy victim" was carrying his wallet in an inside pocket of a suit jacket, he was an easy mark.