Dave Phillipson, the organizer of CEO Space, a California-based network of entrepreneurs, said he had been working on starting an internship program this summer but abandoned it “because of this silly ruling.”

Image Kathryn Ciano, left, is an intern at Fox. Credit... Joshua Bright for The New York Times

“I was an unpaid intern and I had no problem with it,” he said.

The Atlantic Media Company, which publishes The Atlantic Monthly magazine and other print and digital publications, decided this spring to start paying its interns immediately — and even compensate last year’s interns retroactively. Many employers, however, especially those who have long-established unpaid internships, were reluctant to comment about whether they have instituted changes.

But at least one employer has been outspoken. John Stossel, a former anchor on ABC’s “20/20” who now hosts his own show on the Fox Business Network, has been sounding off about the issue all over print, the airwaves and cyberspace. He even donned a police uniform for an appearance on the Fox News program “America Live” to ridicule the crackdown.

“I’ve built my career on unpaid interns,” he said in the interview, “and the interns told me it was great — I learned more from you than I did in college.” (Asked why he didn’t pay them if they were so valuable, he said he didn’t have the money.)

Many people believe a focus on unpaid internships is an important effort to protect young people from economic exploitation, as well as to even the intern playing field so students who can afford to work without pay aren’t the overwhelming beneficiaries of internship experience. But some worry that the crackdown may actually limit their opportunities.

Sarah Green, a 20-year-old art history major at Emory University, landed a prestigious internship last summer at the Metropolitan Museum of Art. This year she hoped to return to the New York art world. She applied to every auction house and museum she could find for both paid and unpaid spots. Every place turned her down, with some explaining they’d cut back on the number of interns they now hire. The experience may have been a career-changer for Ms. Green. “I took this as a sign that I was not meant to work in the fine arts,” she said. Instead she enrolled in summer courses in graphic design and advertising and has now decided to apply to a graduate program in art direction for advertising.