MEXICO CITY — The phone call begins with the cries of an anguished child calling for a parent: “Mama! Papa!” The youngster’s sobs are quickly replaced by a husky male voice that means business.

“We’ve got your child,” he says in rapid-fire Spanish, usually adding an expletive for effect and then rattling off a list of demands that might include cash or jewels dropped off at a certain street corner or a sizable deposit made to a local bank.

The twist is that little Pablo or Teresa is safe and sound at school, not duct-taped to a chair in a rundown flophouse somewhere or stuffed in the back of a pirate taxi. But when the cellphone call comes in, that is not at all clear. This is “virtual kidnapping,” the name being given to Mexico’s latest crime craze, one that has capitalized on the raw nerves of a country that has been terrorized by the real thing for years.

“This reflects the fear in Mexican society, the collective psychosis about kidnapping,” said Adrienne Bard, an American radio journalist who has lived in Mexico for more than 20 years and who received a call in March from a crying young woman. Shocked, she thought it was her own college-age daughter.

A new hot line set up to deal with the problem of kidnappings in which no one is actually kidnapped received more than 30,000 complaints from last December to the end of February, Joel Ortega, Mexico City’s police chief, announced recently.

Last November, more than a dozen members of Mexico’s Congress received calls saying that their children had been taken, prompting the legislature to suspend business for the day.

Security was tightened, and one lawmaker, Mirna Rincón, of the governing National Action Party, collapsed in her chair when she received the call saying her son had been grabbed. A photograph taken by the government news agency Notimex shows someone fanning her grief-stricken face.