(CNET) — A rights group has slammed Facebook for allowing a child bride auction in South Sudan to take place on its platform.

The father of a 16-year-old girl reportedly received 500 cows, three cars and $10,000 in exchange for his daughter’s hand in marriage, according to children’s rights group Plan International.

“This barbaric use of technology is reminiscent of latter-day slave markets,” George Otim, Plan International’s director for South Sudan said in a post last week on its website. “That a girl could be sold for marriage on the world’s biggest social networking site in this day and age is beyond belief.”