The airline industry appeared to be caught off-guard when a 17-year-old Bollywood actress took to social media alleging she was sexually assaulted on an airplane. Her claim which was denied by the accused on a domestic Vistara flight in India has activated an outrage online and given rise to a rare police investigation.

Recently, Facebook founder Mark Zuckerberg’s sister, Randi, a Silicon Valley executive, also reported via social media that she had been a victim of sexual harassment on an Alaska Airlines flight. These incidents reflect a risk to airlines which they need to act more than just respond once an incident goes public and their brand comes under fire.

A London-based analyst at Strategic Aero Research, Saj Ahmad, said, “It’s a global issue and every country has to deal with the fallout. Being prepared to address passenger concerns rather than being reactive to social media complaints will arguably help address these problems in real time.”

According to the International Air Transport Association (IATA) last year, airlines globally reported just 211 instances of “inappropriate sexual behavior”, among 3.8 billion passengers on more than 40 million flights. There are so few police investigations because less than half of those cases were reported to the authorities.

Taylor Garland, spokeswoman for the U.S. Association of Flight Attendants believed that under-reporting occurs but said that victims are required to press charges which the airline can’t do for them.

The director general of the Association of Asia Pacific Airlines, Andrew Herdman, said the IATA data needs to be seen with caution “as event descriptions are not always standardized” and there are “significant variations in the level of voluntary reporting by airlines.”