Jan. 22, 2010 -- An "alarmingly high" number of high school students are reporting sexual advances from their adult bosses and other supervisors at some of the country's best known fast food operations, according to an official of the Equal Employment Opportunity Commission.

"It's an incredibly serious problem," said William Cash, a trial attorney with the EEOC, in an interview to be broadcast tonight on the ABC News program "20/20."

"Employers that choose to use high school kids to work have a responsibility to protect these young people," Cash said. "We don't want them to be fondled, we don't want them to be raped."

Watch "20/20" tonight at 10 p.m. for the full report.

The issue is being raised in a number of lawsuits, including cases now pending in California against Starbucks and a McDonald's franchise owner.

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Kati Moore of Orange County, CA claims a 24-year old supervisor at Starbucks made almost daily demands on her for sex, months after she began working as a 16-year old barista.

"I felt like I didn't have a choice," Moore, now 20, told ABC News."I was ashamed and embarrassed. And I felt like he had complete control over my job... he knew all this stuff about my family and my friends and my school."

She says the supervisor would summon her for sex in hundreds of text messages, including one that said, "I'd liked to f--- tomorrow."

"It was an everyday, numerous times a day occurrence," Moore said. "And I just saw it and did what I had to do."

She says other Starbucks supervisors and managers knew what was happening but did nothing to stop the illicit relationship.

After the young woman's mother learned of the relationship, she alerted prosecutors who brought criminal charges against the Starbucks employee, Tim Horton. After claiming he did not know the barista was 16 years-old, Horton pleaded guilty to a felony charge of illegal sex with a minor and served four months in prison.

The family has sued Starbucks claiming the company failed in its responsibility to protect the young woman from Horton.

Starbucks executives declined to be interviewed but in a statement the company said, "These two employees concealed their relationship from Starbucks, which violated company policy. We are confident that the case will ultimately be resolved in finding that Starbucks is not at fault."

Click here to read Starbucks' full statement.

Read another statement from Starbucks.

Hard Ball Tactics

The case turned ugly as the Starbucks law firm, Akin Gump, used hard ball tactics to defend their client, including successfully seeking to make public the young woman's sexual history once it learned she had been interviewed for "20/20."

"They are trying to defend themselves by calling me a slut," she told "20/20." "It's intimidation. It's harassing to sit though deposition and just be re-victimized."

Federal judge Andrew J. Guilford agreed with Starbucks lawyers and ordered the information unsealed because of the company's need "to defend themselves" and "level the playing field."

Starbucks disclosed in court papers that the woman has had sexual encounters with 12 men other than Horton, seven of them before she met Horton.

Starbucks says it does have a strict policy against sexual harassment and managers dating baristas, but there is nothing specific about relationships with teens under the age of 18.

The case against McDonald's was brought by another 16-year old employee, Kasey Ramirez, who says a 23-year old shift supervisor lured her into a back storage room and put his hands around her waist and pulled her close.

"He said, 'It's okay, don't be scared, you can trust me,'" Ramirez told ABC News. "I thought his plan was to try and rape me."

She said she broke away and went to another supervisor in hysterics, who she says told her not to be so upset because everyone knew the shift supervisor, who was later fired, was a pervert.

In a statement to ABC News, the McDonald's franchise owner Michael Godlove said there is a "strict policy prohibiting any form of harassment in our restaurants."

"When Ms. Ramirez complained about the incident, which occurred in 2007, we responded promptly and took appropriate action," the statement said.

Click here to read the full statement from McDonald's.

In another case, a manager at a Taco Bell restaurant in Memphis, TN pleaded guilty to raping two of his 16-year-old high school workers, one of whom became pregnant.

"The first victim worked for him about two months before she was raped. The other young lady, he attacked her on the first day that she was working for him," said Cash, the trial attorney for the Equal Employment Opportunity Commission.

Taco Bell

In a consent decree with the EEOC, Taco Bell, while denying any wrongdoing, agreed to pay several hundred thousand dollars to the teens and to begin a training program for its managers about dealing with high school employees.

In a statement Taco Bell told ABC News, "We are outraged that this situation occurred and committed to maintaining a workplace free from harassment in all of our restaurants."

Click here to read the full statement from Taco Bell.

"They make enormous profits based on the work of high school kids, and that's fine," said Cash. "That can be a great working relationship in many cases. But employers that choose to use high school kids to work have a responsibility to protect these young people."

What happened to Kati Moore is not uncommon, experts say. The problem is especially prevalent in fast food restaurants where so many teenagers have their first jobs, said Dr. Susan Strauss, a consultant on corporate harassment.

"They're vulnerable, they're young, they're new to the workforce," Strauss said of the teenage employees.

One in three high school students reported unwanted sexual advances in the workplace, according to a study in Maine.

Watch "20/20" tonight at 10 p.m. for the full report.

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