Expert Talks Dangers and Safety Tips for Children With Pokemon Go

Earlier this week, police arrested a paroled sex offender for playing the hit game with children, which takes players outside looking for virtual monsters.

The makers of Pokemon said this morning that they're working with the National Center for Missing and Exploited Children to keep kids safe as they play the game. Callahan Walsh, a child advocate with the center, stopped by "Good Morning America" today to discuss his organization's work with the game maker.

"We've had a long relationship with Pokemon for a while now ... helping them craft policy and make sure their game is as safe as possible," Walsh said. "They want to make sure kids are safe whether they're playing the card game in the tournaments or they're playing Pokemon Go."

New York City Police Commissioner Bill Bratton has said he's concerned about the safety of all players, not just children.

"That craze is one of the stupidest ones that I've seen, don't understand it, don't intend to understand it," Bratton said. "It has no appeal to me and at the same time people are putting themselves at great risk being lured into certain neighborhoods that they have no knowledge of ... and subjecting themselves to potentially being victims of crime."

Walsh said parents should use the game as an opportunity to teach broader safety lessons to kids.

"The rules that apply to keep kids safe, whether they're walking to or from school or at the bus stop, are going to be the same rules that keep them safe while they're playing Pokemon Go," Walsh said. "We want parents to make sure that they're supervising their youngest children ... [and that] the older children ... [are] empowered with safe and smart decision making."

Walsh listed four safety rules that young players should take before playing the game:

1. Check with a parent before going anywhere.

2. Take a friend.

3. Tell people "no."

4. Tell a trusted adult if anything happens.