Military bases, hospitals and subway operators have joined in the chorus warning players of Pokemon Go to be careful when walking around, eyes locked onto their smartphones in search of those virtual creatures.
Alaska Airlines added its voice last week, saying that playing the hugely popular game at an airport could not only anger already flustered travelers but could incite a confrontation with police.
The game, which launched earlier this month, uses the GPS and camera on a smartphone to let players walk around in the real world while searching for, capturing, battling and training Pokemon creatures that appear on the phone screen.
Pokemon players have been spotted wandering into a municipal airport near downtown Anchorage, a military base near Honolulu and on subway tracks in Toronto and New York City.
The creators of the game said they are trying to remove locations that don't want to be part of the game, such as Arlington National Cemetery outside Washington, D.C.
Alaska Airlines warned in a blog post that someone who stops suddenly in a busy airport corridor to catch an imaginary creature "runs the risk of tripping your fellow travelers."
Travelers should also "avoid playing in security lines, near doorways to restricted areas or anywhere that you might get yourself tackled by airport police," the airline warned.
"You don't want to accidentally chase a Pikachu the wrong way through a security exit and have security chasing you down instead," said Abbey Elliott, social media program manager for the Port of Seattle, which operates the Seattle-Tacoma International Airport.
A spokeswoman for Los Angeles International Airport said they have yet to notice any problem with Pokemon Go players at LAX.