It’s not hard. The Chronicle has the story here, which involved an experiment with a fake online class the professors set up to see if they could detect cheaters:
“Joey” emailed that he needed someone to take a 10-week accelerated course in introductory psychology, and inquired if the company was prepared to handle all aspects of the class. The company would not only take the whole course for Joey, its representative said, but promised to earn him an A.
After asking Joey for his contact information, which he submitted on the company’s website, and a copy of the course syllabus, the company sent him an invoice for $917. Joey asked to make the payments in two installments. He made the first using a prepaid credit card. Halfway through the course, he paid the second installment in the same way.
After receiving the first payment, the company took the first weekly quiz, earning a nearly perfect score. Soon afterward, it requested Joey’s help in purchasing a required textbook (he provided electronic access). From that point on, the company completed all of Joey’s work without any input, including quizzes, examinations, and discussion-board posts, receiving an A on every assignment.
… In the end, the professors caught several students plagiarizing material. But they did not detect that Joey Sanchez was a fraud. Both instructors gave him an A in the class.
“I certainly did not feel that ‘Joey’ was being ‘run’ by a cheating company,” Mr. Malesky wrote in the paper. “If anything, Joey struck me as a conscientious and motivated student who wanted to get as much out of the course as possible.”