With the dark web on there, the content is becoming more prevalent and more horrific, said Matt Wright, the chief for the Child Exploitation Investigations Unit at Homeland Security Investigations.
Agents work on probes involving money, drug smuggling or child sex trafficking.
Agents and investigators initiated 4,224 child exploitation cases that resulted in 3,771 arrests and identification of 1,066 victims.
President Barack Obama signed a law in February 2016 mandating notification when registered sex offenders traveled.
The notice doesnt impede legal travel, but it does give countries a heads-up, especially in locations where child sex tourism and abuse are rampant, officials said.