Why are mobile gamers so crazy over Pokémon?

People are searching under their desks, running into streets, and trying to sneak backstage at Disney to catch virtual video game characters. The latest mobile gaming craze, Pokémon Go, has drawn millions into a nationwide scavenger hunt. But it’s not all fun and games. Police in Missouri believe four armed robbery suspects lured their victims through Pokémon. And while playing the game, one teenage girl found a dead body lying in a river in Wyoming.

The 1990s hit Pokémon made its mobile return this month in the augmented reality game Pokémon Go, becoming an overnight sensation. Since its U.S. release on July 7, the app has an estimated 7.5 million U.S. downloads and is making $1.6 million a day. Pokémon Go is also set to overtake Twitter with its higher daily user ratings. Even churches are getting involved with efforts to entice players to venture into sanctuaries.

But all this virtual mania comes with a price—risking users’ private information and, in some cases, their safety.

Pokémon Go taps into the GPS and clock on users’ phones and makes Pokémon characters “appear” around users on their phone screens. The goal of the game is to encourage users to travel to designated locations, known as “Poké Stops,” to catch the Pokémon.

The original Pokémon video games published by Nintendo took place in a fantastical world where people called “trainers” got exotic creatures to fight each other. The new game allows fans to imitate the Pokémon experience in this world. But the app has had its share of controversy, due mostly to its privacy settings.

Cyber security experts note the game asks iPhone users to sign in with their Google accounts. But unlike most apps, Pokémon Go requests “full access” to users’ Google accounts, meaning the app could “see and modify nearly all information”—including private emails.

The game’s developer, Niantic, acknowledged the error and said it only wanted surface-level information, like user IDs and email addresses. Niantic has promised to fix the problem and change the app’s permission settings.

Despite the technical errors, churches have capitalized on the game to reach younger audiences. Along with other landmarks and buildings, some churches have become Poké Stops, and advocates recommend churches be proactive and purchase “Lure Modules” to draw the Pokémon and game users into their facilities.

Others praise the virtual reality game because it requires users to move. “Pokemon Go got more kids to do exercise in 24 hours then Michelle Obama did in 8 years,” tweeted Morgan Hart. “Pokemon Go might be the most exercise we’ve gotten as a nation since those Harlem Shake videos,” wrote Ian Simkins.

Despite the potential for ministry and exercise, law enforcement officials have been vocal about the need to play the app responsibly.

The Highway Safety Office in Tennessee took to Twitter with a Photoshopped image of a distracted driver about to cause a wreck while playing Pokémon Go. The image says, “Wait to Go until you’ve stopped” and includes the hashtag #PikachuCanWait.

Other police departments have had issues with users sneaking around at night trying to catch Pokémon characters.

“We have had some people playing the game behind the PD, in the dark, popping out of bushes, etc.,” the Duvall city Police Department wrote on Facebook. “This is high on our list of things that are not cool right now. … Let someone behind the counter or an officer know you are looking for an imaginary critter thing and make sure that your presence is well-known.”