Randi Zuckerberg, the sister of Facebook Inc. founder Mark Zuckerberg, isn’t the first to complain about sexual misconduct on jetliners — a problem a prominent flight attendants’ union called a “silent epidemic” that airlines have failed to solve.

Randi Zuckerberg, founder and chief executive officer of Zuckerberg Media, said this week that a male passenger on an Alaska Air Group Inc. flight made repeated harassing comments to her and airline employees did nothing about it. In a letter to the carrier posted on social media, she said the crew members continued to serve the abusive customer alcoholic drinks and told her not to “take it personally.”

Zuckerberg’s description of the incident on a trip from Los Angeles to Mazatlan, Mexico, drew widespread media attention and Alaska Airlines temporarily revoked the passenger’s travel privileges, pending an investigation. Still, airlines must take stronger action to crack down on in-flight sexual harassment and assault, said Sara Nelson, international president of the Association of Flight Attendants-CWA.

“Let’s be clear that this is not an Alaska problem,” Nelson said in a statement Thursday. “It is an issue at the forefront of national awareness and it is a critical time for the airline industry to examine the steps necessary to take this on.”

Nelson said she is seeking a zero tolerance policy and specific regulations to address the issue. “For too long unacceptable sexual innuendo, harassment advances, and assault have been a silent epidemic in our society and certainly on our planes,” she wrote.

Such incidents across all industries are under heightened scrutiny as more women go public with allegations against powerful men, from film producer Harvey Weinstein and actor Kevin Spacey to U.S. Representative John Conyers and U.S. Senate candidate Roy Moore. NBC fired “Today” show host Matt Lauer this week after allegations of sexual misconduct surfaced.

The AFA conducted a member survey last year that showed the majority of flight attendants had no knowledge of written guidance or training on this specific issue available through their airline, Nelson said. Sexual harassment training is only mandatory in California, Connecticut and Maine, although most large companies have training for at least some of their employees.

The survey of about 2,000 attendants also found that 20 percent of crew members had experienced a report of a mid-flight sexual assault by a passenger against another passenger, and in those cases law enforcement was contacted or met the plane only about 40 percent of the time.

Allison Dvaladze said she was assaulted while flying to Amsterdam in April of last year. The incident, which is still under investigation, prompted her to start the Facebook page, “Protect airline passengers from sexual assault.” She also worked with U.S. Senator Robert Casey, from Pennsylvania, to introduce the “Stopping Assault while Flying Enforcement Act of 2017,” which was referred to committee in July, she said. The law would require crew training and better data collection on assault in the air.

“I travel a lot, I had never heard of this before it happened to me,” said Dvaladze, who flies as part of her work to bring cancer screening to under-represented groups. “It was a real shock to me when it happened. But what was more of a shock to me was that it wasn’t a surprise to the crew, yet at the same time they had no idea what to do. If the crew isn’t armed with the right tools, they can’t handle it.”

‘Very Disturbing’

In a Thursday blog post on Alaska Airlines’ website, Vice President of People Andrea Schneider addressed a case of sexual harassment on an Alaska flight from Los Angeles to Mazatlan. Schneider called the report “very disturbing” without identifying the accuser.

“The safety and well-being of our guests and employees is our number one priority,” Schneider wrote. “As a company, we have zero tolerance for any type of misconduct that creates an unsafe environment for our guests and our employees.”

Zuckerberg’s comments on Twitter and Facebook prompted thousands of comments and shares, many from women who said they had been harassed on flights and ignored by flight crews and the airlines. Zuckerberg said on Facebook that she didn’t identify the passenger because she didn’t want to make it a “personal vendetta.”

Carriers take the issue seriously, said Vaughn Jennings, spokesman for trade group Airlines for America.

“Employees receive extensive customer-service training to ensure the safety and well-being of all our passengers,” he said in a statement.

Zuckerberg, who is a former marketing executive for Facebook, said on Twitter that she felt “disgusted & degraded” by the experience. She later said she came away with a better view of the airline’s response after talking with the company.

“I just got off the phone with two executives from @AlaskaAir who informed me that they are conducting an investigation and have temporarily suspended this passenger’s travel privileges,” Zuckerberg said on her Twitter account. “Thank you for taking this seriously.” Bloomberg