In some instances, the coronavirus has undercut them further.
Facebook, which also owns Instagram, last month announced it was sending its content reviewers home due to the coronavirus threat, and would be increasing its use of automated software to detect inappropriate content. Last week, the company said technological improvements helped it "take down more child nudity and sexual exploitative content" on its platforms in recent months, but authorities remain skeptical and say a huge amount of illegal material continues to circulate.
As a result, parents must be vigilant, they said.
"That's always been the message, but as things change -- technology changes, social media evolves -- parents need to keep up on that stuff," Cato said.
Experts warned the growing number of unchecked reports comes as other safety nets for children have collapsed, children are becoming increasingly vulnerable and sexual predators are getting bolder.
With children stuck at home and away from their friends and teachers, reporting of suspected child abuse and neglect has fallen off dramatically, officials have noted.
"In this time of shelter in place, unfortunately children don't have a lot of contacts with mandated reporters: teachers, mental health providers, coaches, mentors," said Laura Abrams, chair of the Department of Social Welfare at the UCLA Luskin School of Public Affairs.
At the same time, many children are more exposed now to adults in their households who may want to harm them, the FBI warned last month.
Of the millions of tips funneled through Shehan's organization, the vast majority of offenders are overseas, and never come into direct contact with their victims. Parents who think their kids are safer than ever staying at home need to realize that, officials said.
"They're not always trying to meet up with (kids) at a location, like (NBC's reality TV show) 'To Catch a Predator.' They are abusing them on the internet," Meares, the LAPD detective, said. "They don't have to meet a child to sexually abuse them. They do it via livestream."