Two men carrying handcuffs and leg irons came for him at his mother's home in Sacramento, Calif., shoved him into a van and bound him hand and foot. They drove him 12 hours south, over the Mexican border, into a high-walled compound near here called Casa by the Sea.

"It was nighttime," Ryan recalled. "I look around and I see kids sleeping on cement. I was really, really scared. The big honcho, Mauricio, said, `You don't speak English here.' I didn't know how to speak Spanish."

Ryan quickly learned the rules: stay silent, be compliant, don't look up, don't look out the window, don't speak unless spoken to. The punishments for breaking the rules included solitary confinement, lying on the floor in a small room, nose to the ground, often for days on end.

Ryan was not a criminal. He was only skipping school, his parents said in telephone interviews. But in August 2000, they said, in the middle of a bitter divorce and custody battle, they decided to send him away to Casa by the Sea, which calls itself a "specialty boarding school" for behavior modification.

Like hundreds of other parents, the Fraidenburghs made their choice largely on the basis of a glossy brochure and a call to a toll-free number in Utah. They came to regret their choice.

The idea of sending a child to such a program in Mexico was unheard of a decade ago. But in the United States, behavior-modification programs and boarding schools for troubled youths have faced increasing legal and licensing challenges over the past few years.

More and more are moving abroad — some to Mexico, Central America or the Caribbean — where they operate largely under the regulation radar and where some employ minimum-wage custodians more than teachers or therapists, say government officials, education consultants and clinical psychologists.

The behavior-modification business is booming at Casa by the Sea, on Mexico's Pacific Coast, the largest of 11 affiliated programs with roughly 2,200 youths, about half of them in Mexico, Costa Rica and Jamaica. The programs are run by a small group of businessmen based in St. George, Utah, under the banner of the World Wide Association of Specialty Programs and Schools, or Wwasps, and Teen Help, the programs' main marketing arm.

Over the past seven years, local governments and State Department officials have investigated Wwasps-affiliated programs in Mexico, the Czech Republic and Samoa on charges of physical abuse and immigration violations. The Mexican program, in Cancún, and the Czech program closed, and their owners left those countries saying they feared unjust charges. The Samoan program cut its affiliation with Wwasps.

Ken Kay, the president of Wwasps, would not allow a reporter to visit Casa by the Sea; Dace Goulding, the program's director, declined to answer any questions. But Mr. Kay, responding to inquiries in writing from his office in Utah, said no charge of abuse had ever been proven against any of the programs in any court.

"We are about getting families back together," he said in a written statement. "We are not for everyone, and there are very few but vociferous critics of not just us but any youth intervention." He described many of the program's critics as parents who feel they have been "manipulated, brainwashed or duped" or who are battling through divorce and taking their anger out "by making us look terrible."

In telephone interviews, eight teenagers who were formerly in Casa by the Sea described a system in which the youths try to ascend six "levels" through a system of rewards and punishments, including being sent to "R and R," a small, bare isolation room, often for days on end. Discipline, not education, was the rule, they said.

For Laura Hamel, 17, of Vienna, Va., who counts herself as a success story, it was a slow two-year ascent to graduation in March. She said she was demoted from Level 3 back to Level 1 after giving a weeping, lonely friend a hug and a kiss on the cheek at Thanksgiving. Affection of that kind is forbidden.

A youth who rises to Levels 4, 5 and 6 can become a "junior staff member" and "participate in the discipline process" against lower-level youths, Casa's contract with parents says.

"The authority is in your hands," said Ryan Pink, 19, of El Paso, who reached Level 5 at Casa. "You can discipline kids. The younger kids — they were constantly being restrained, being punished, put in R and R for four or five days. Nose to the wall. Or nose to the ground. And at night you sleep in the hallways."

Many parents and youths say the behavior-management system of discipline and punishment scares youths into sobriety and obedience. Others — parents and youths formerly enrolled, education experts, government authorities and a former Wwasps program director — say the programs profit from struggling parents unable to handle their depressed, delinquent, defiant or drug-abusing children.

"Their goal is not to help teens in crisis or their families," according to a former director of one Wwasps-affiliated program, Amberly Knight. "It is to make millions of dollars."

The financial success of Casa by the Sea is evident. Its enrollment has nearly tripled, from about 200 youths when it opened in 1998 to more than 570 today, almost all American teenagers. Already among the biggest programs of its kind outside the United States, Casa by the Sea has just spun off another program for those 18 and over.

Tuition and fees at Casa by the Sea run about $30,000 a year, half of what some United States-based programs cost. Its staff members "do not need and may not necessarily have" teaching credentials, Casa's contract with parents plainly states.

Lon Woodbury, publisher of Woodbury Reports, which rates schools and programs for troubled teenagers inside and outside the United States, said one reason that American programs have moved abroad is "to avoid the laws and regulations of the States." He added, "They can hire minimum-wage staff and still charge stateside prices."

Profit margins and growth within the programs run by Wwasps appear solid. Teen Help, the affiliation's main marketing arm, was the single biggest corporate campaign contributor in the state of Utah in the 2002 election cycle, donating $215,290 to Republican campaigns, according to online federal election records posted in March.

Mr. Kay, the Wwasps president, said that the proof of the programs' success is the way in which "behavior of students generally changes drastically." The organization's internal surveys, he said, proved that "more than 98 percent of the schools' parents are completely satisfied." He wrote, "No wonder these are the fastest growing Schools of their kind in the world!!!"

The overseas "specialty boarding school" industry is growing so fast that United States consular officials in overseas embassies say they have no idea how many such programs exist.

"No authorities in Mexico control these institutions," said Elisa Ledesma, a lawyer at the American Consulate in Tijuana. Consular officers demanded and received access to several such programs in Mexico, one official said, after they "heard horror stories from parents."

The consular officers have the power, under the Vienna Convention, to visit overseas programs to check on the well-being of American citizens under 18.

In January, after several such visits, the State Department issued a notice on "behavior modification facilities" in Mexico, Costa Rica and Jamaica. The programs may "isolate the children in relatively remote sites" and restrict their contact with the outside world, it said.

At least seven programs in Utah, Montana, South Carolina and New York are Wwasps affiliates, according to the organization's Web site; at least three have faced legal challenges. Utah state officials say they are reviewing the license of the flagship Wwasps program, Cross Creek Manor, and that a second program, Majestic Ranch, is operating without a proper license.

Six weeks ago, according to the state attorney general's office in Utah, a director of Majestic Ranch entered into a court agreement to have no unsupervised contact with children after he was charged with misdemeanor child abuse.

Attorneys for both programs contest the licensing challenges. South Carolina officials have fined a third Wwasps program, Carolina Springs Academy, $5,000 for operating without a license.

While some dissatisfied parents have sued Wwasps and its programs, the contract that parents sign with Casa by the Sea sets high hurdles for them. It states plainly that the program "does not accept responsibility for services written in sales materials or brochures" or promises made by "staff or public relations personnel" and that any dispute between a parent and the program must be settled in a Mexican court, not in the United States.

The Wwasps programs market themselves under a multitude of interlinked Web sites. Their sales personnel offer thousands of dollars in incentives to adults who recruit new youths or host Web sites advertising the programs.

Some parents said in interviews that they enrolled their children in programs they had never visited after browsing Web sites, brochures and videotapes depicting happy children in a wholesome setting.

"I sent him there sight unseen," said Patti Reddoch, of Sweeny, Tex., who considered Dundee Ranch for her son, Edmund Brumaghin, now 17, but chose Casa by the Sea instead. "The music he was listening to started getting darker and he was getting more into the drugs, and that's when I decided I needed to do something.

"So I went on the Internet and started searching around and found the Wwasp program. I contacted them and made the arrangements, and that's pretty much it. It didn't take me any time at all."

Mrs. Reddoch, speaking by telephone, said she then hired an "escort service" familiar with Casa by the Sea to handcuff and transport her son away at 5 a.m. one Sunday last September.

That morning, her son cursed her bitterly, but now his attitude is changing, she said.

"I am very pleased with the school," said Ms. Reddoch, who said she visited Casa by the Sea once, for a weekend, last January. "I've started putting out brochures for referrals. I would recommend Casa to anyone."

Reality may differ from the brochures, however. "Everyone has a shaved head," Michael Zieghelboim, who was formerly enrolled at Casa by the Sea, said in a telephone interview. "They walk around like zombies. Most of the staff have no training."

"Casa by the Sea was the scariest thing that ever happened to me," said Mr. Zieghelboim, who now lives with his father in El Salvador.

He said that despite falling behind in his education at Casa by the Sea — at 17, he is now in the 10th grade — he rates himself a success. "If I had never gone there, I'd probably still be doing cocaine," he said.

This kind of tough discipline is an attraction for many exasperated parents.

The program runs "a very tight ship," said Virginia Day, of Redmond, Wash., who sent her son, Gabriel, 15, to the program in July.

"The staff that works most closely with the kids are not necessarily professionals, and I know that this is an issue," said Ms. Day, who called herself a very satisfied customer. "This is not a school that specializes in a therapeutic component."

Carol Maxym, an educational consultant in Maryland, said: "What they are looking for at Casa is compliance. Compliance is easy, if you break the kid down enough. And compliance is cheap." She added, "The parents often don't realize what's going on."

Youths and staff at other overseas Wwasps programs have described harsh conditions. One was Aaron Kravig, now 19. He said he contracted scabies, untreated for six months, ate meals of watery porridge and fish entrails, and was schooled almost solely with "emotional growth" videos at Tranquility Bay, the Wwasps-affiliated program in Jamaica, according to a transcript of sworn testimony he gave last year at a Virginia state court hearing.

In Costa Rica, Ms. Knight, the former director of the Wwasps-affiliated Academy at Dundee Ranch, resigned in August after sending a letter to the national minister of child welfare calling for the program to be shut down.

The letter said the program was "hiring unqualified, untrained, staff" and providing "the bare minimum of food and living essentials." It said the program "takes financial advantage of parents in crisis, and puts teens in physical and emotional risk."

The speed with which some parents choose an overseas behavioral-modification program for their children baffles some educational consultants.

"I find it incredible that parents would send their kids off to some place they've heard about on the Internet," Mr. Woodbury said.

Ms. Maxym, author of "Teens in Turmoil: A Path to Change for Parents, Adolescents and their Families" (Viking Penguin, 2000) said, "I find it interesting that parents will spend less time finding a school for their child than buying a new car."

Ryan Fraidenburgh's father, Bob, an aerospace engineering executive, said he had only glanced at Casa by the Sea's "brochures that looked like Club Med." He said he removed Ryan from the program by himself in January 2001 after deciding he had been too hasty.

"We made a huge mistake," he said. "Until the day I die I'll regret that."

Ryan's mother, Carolyn, said: "We were expecting treatment, not a minimum-wage person to watch over your kid like he was an animal in a cage."