Student resistance to the Bloomberg administration’s cell phone ban in schools is creating an underground economy around New York City: For a charge, local businesses are storing the electronic devices while the children are in class. Already, though, the cell phone storage business is creating new headaches for students and store owners, as the makeshift depositories have become targets of theft.

On Thursday, a crowd of students from Washington Irving High School near Union Square descended on a local news store, NYC Universal News, to pick up their cell phones. They flashed ID cards to prove which phones and iPods were theirs, and a store clerk doled them out until a shy freshman girl silently put her ID on the counter. The clerk, Shaikat Taher, explained that she could not collect her phone as it was one of four that had been stolen that day by a group of teenagers. “I know we are responsible,” Mr. Taher said, “but you have to complain to the police first.” He added that he had filed a report with the precinct earlier in the day. Stunned, the girl left.

Students and store owners say such scenes are common, thanks to the city’s school cell phone ban, which has been increasingly enforced in the past year. While many schools turn a blind eye to cell phones that are turned off, schools with metal detectors actively confiscate them.

To avoid losing their phones, students are turning to local businesses that store them for fees as high as $2 a day. Students and store owners alike say this solution is unreliable.

“From tomorrow, we’re not keeping them anymore,” Mr. Taher, whose family owns the store near Union Square, said. Mr. Taher originally held phones for only a few customers. He charged no fee, but students say they had to buy something to stash a phone.

Soon, dozens of students were asking to store their phones, causing commotion and providing a distraction that Mr. Taher said was a boon to shoplifters. On Thursday, he said, a student ran off with several phones.

The crime fits a familiar pattern. A sophomore at Washington Irving, Rajendra Mohabir, said that last year he and other students paid a Laundromat $2 a day to hold phones, only to see the service end when a student’s phone was stolen.

A sophomore at Louis Brandeis High School on the Upper West Side, Samantha Bonilla, says a nearby grocery store held phones up until a theft occurred and the owners had to reimburse a student for the phone.

A spokeswoman for the Department of Education, Dina Paul Parks, said she could not comment on what students do outside of school. Council Member Peter Vallone Jr. of Queens, an opponent of the ban, called the underground market for storage “unfortunate.”

Although his opposition to the ban stems from safety concerns, Mr. Vallone said was adamant that city policy should “not involve negotiations between an 8-year-old and a bodega owner.”

Mr. Vallone also said he was worried that the ban teaches students to ignore authority. “It’s like prohibition,” he said. “We’re raising a generation of smugglers.”

Because storage places are not reliable, “smuggling is more common,” a Louis Brandeis High School sophomore, Alfredo Hernandez, said.

Students describe an array of techniques to get past metal detectors, many which seemingly could be applied to weapons. Girls hide phones in their shirts and tell guards they wear under-wire bras. Students wrap phones in tinfoil and pretend they’re sandwiches. Some students hide phones in their hair, others cut out hidden pockets in steel-tipped boots.

To avoid the metal detector entirely, some students even bury phones, wrapping them in plastic or tinfoil and digging a hole by nearby bushes.

“Smuggling is hard the first time,” Ms. Bonilla said. “But you get confidence fast.”

A senior at La Guardia High School on the Upper West Side, Erik Coniglione, said he buried his phone this summer instead of using a nearby deli that charges $1 a day. A junior, Jackie Chang, said she buried her phone as well, but it was stolen. Ms. Bonilla said many Brandeis students buried their phones in flowerbeds until security guards and thieves caught on and dug them up. She said she was more impressed with a friend’s new technique: taping a cell phone to the bottom of a subway station bench. “She scraped the gum off first,” Ms. Bonilla added.

When asked why they needed their cell phones, students often said it was to contact their parents. A recent La Guardia graduate, Jena Caputo, said her commute from Staten Island was an hour and a half each way and that the 2003 ferry crash left her parents uneasy. “God forbid something blows up, you need your cell phone,” a junior at Washington Irving High School, Kevin Moore, said.

Mr. Vallone said he is concerned his two daughters, who are in public schools, would be unable to reach him in an emergency. Ms. Paul Parks said schools could guarantee students’ safety. One possible solution is slowly moving forward. The city is implementing a pilot program under which private vendors would set up secure lockers at their own expense outside schools. Students would pay a small daily fee to store their phones and other belongings.

Ms. Paul Parks said the program is under review and was intended to begin this year, but is behind schedule. While Mr. Vallone said the locker proposal is “not ideal,” he said it may be an appropriate compromise.