Pokémon Go is nothing short of a phenomenon, as these headlines about the viral reality mobile game just in the past few days attest:

‘Somebody stole my Pokémon’: Pokémon Go player calls British police over missing cartoon monster

Pokémon Go crash is proof texting and driving has gone too far

How to get started playing Pokémon Go

All around the world, authorities are worrying about Pokémon Go

The concerns mentioned in the above headline include fears that some people will neglect their work and spend all day playing the game, or that Pokémon Go “reeks of Satanism,” as Andrei Polyakov, a Cossack leader in St. Petersburg, was quoted as saying.

But now there are new fears being raised about the game — which essentially allows players to “locate” Pokémon figures in actual locations through the use of the phone app — by Common Sense Media, a nonprofit based in California that works to promote the safe use of media and technology by young people.  James Steyer, the organization’s founder and chief executive officer, has written the letter below about children’s privacy concerns to John Hanke, chief executive officer of Niantic Inc., which makes Pokémon Go. I have asked Niantic for a response and will post it if/when I get it.