(Recasts, updates with quotes from District Attorney, Human Rights Watch)
By Ellen Wulfhorst
WASHINGTON, April 25 (Thomson Reuters Foundation) - Sex traffickers are growing more adept at using sophisticated technology to exploit people, especially tools to hide their identity and encrypt data, fanning an ongoing battle between online privacy and security, a conference heard on Tuesday.
Websites, chat rooms and virtual currency all are used by traffickers to hunt for child victims and sell them, said Kevin Gutfleish, a specialist in violent crimes against children at the Federal Bureau of Investigation (FBI).
Traffickers advertise online, track victims by cellphones and use encrypted messaging systems to communicate with accomplices, experts say, fuelling debate between human rights advocates who value protection against authorities concerned that encryption hampers law enforcement and enables criminals.
"It has in some cases very significantly adversely affected our ability to solve cases and to get justice for victims," Cyrus Vance, New York County District Attorney, told Trust Conference/America Forum, a one-day Thomson Reuters Foundation event on the fight against slavery and trafficking.
Tech giants Apple and Google have come under scrutiny after changing their operating systems in 2014 to encrypt users' data by default which boosted privacy online but made it harder for law enforcement agencies to get information off smartphones.
Facebook-owned messaging system WhatsApp last year turned on end-to-end encryption that protects messages.
Due to such encryption, Vance said his investigators have more than 500 cells phones that contain potential evidence in criminal cases but are locked and inaccessible.
He called on Congress to pass legislation balancing the interests of security, privacy, law enforcement, crime victims and technology companies.
"We want our privacy, but we also want to make sure that where criminals are involved, there's going to be a way to solve the crimes," he said.
But Human Rights Watch Executive Director Ken Roth said human rights groups value online privacy and encryption in protecting victims, and breaching that privacy wall would create a vulnerability that will be exploited by criminals.
"Yes, there are a handful of crimes that are going to be solved ... but think about the crimes that are going to be committed," he told the Trust Conference/America Forum.
"There are reams of hackers out there, criminal and governmental," Roth said. "And they're going to win."
The FBI's Gutfleish told the Thomson Reuters Foundation that traffickers are keeping up with technology - and exploiting it for their purposes.
"They're not opposed to using what's available to them," he said.
A survey of more than 1,000 law enforcement officers conducted for the Department of Justice last year found more than a third said the technical sophistication and expertise of sex traffickers had increased in the last five years, Gutfleish said.
In particular, they reported seeing an increase in the use of tools and services that protect identities such as proxy servers that can mask the source of communication and the FBI was keeping pace with this and also trying to benefit from this technology.
"Sex traffickers are readily taking advantage of those technologies that are available to them .. You have a lot to lose when you're exploiting children," he said. (Reporting by Ellen Wulfhorst, Editing by Belinda Goldsmith; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, property rights, climate change and resilience. Visit news.trust.org)