“The majority of extortion complaints received in 2018 were part of a sextortion campaign in which victims received an email threatening to send a pornographic video of them or other compromising information to family, friends, coworkers or social network contacts if a ransom was not paid,” according to the FBI.

While the FBI does not break out sextortion from the total number of extortion crimes reported, a spokesperson told CNBC, “The majority of extortion complaints received in 2018 were part of a sextortion campaign in which victims received an email threatening to send a pornographic video of them or other compromising information to family, friends, coworkers, or social network contacts if a ransom was not paid.”

The advice from experts: Don’t fall for it.

“They play on our basest levels of psychology,” said Priya Sopori, partner at law firm Greenberg Glusker and a former assistant U.S. attorney who prosecuted cybercrimes, including sextortion.