Law enforcement agencies around the country are warning iPhone users about a potentially deadly prank involving the Apple iPhone's "virtual assistant" Siri.
According to police, social media posts have been encouraging users to ask Siri about the number "108 if you want laugh."
"The Harris County Sheriff's Office, along with Texas NENA, are encouraging iPhone users NOT to test the '108' command," the Texas department urged in a Facebook post. "The command, in fact, will instruct Siri to call emergency services, which could potentially tie up emergency lines."
That's because the Apple designed Siri to recognize emergency service numbers from anywhere in the world. In India, the number 108 is the equivalent of dialing 9-1-1, so saying it will connect a caller to the nearest 911 dispatch center.
The same feature was also used in the U.K. this month by a boy who asked Siri to call 999 to help his unconscious mother.
Using the code will give someone five seconds to cancel before the call goes through to emergency officials.
Sheriff officials warned that pranks taking advantage of the feature tie up emergency lines and delay response time — which could mean the difference between life or death — for people who are in actually need of help.
Other numbers officials said users should avoid are 112, 110, and 000.
"The 9-1-1 Communications Division tested these numbers and can confirm that dialing or asking Siri about any of these numbers will result in a call being placed to the emergency communications center," an Oregon sheriff's department said in a statement.
Officials say the prank is very dangerous and even criminal in some states.
"Help us spread the word and make our community safe by ensuring those who need the life or death assistance of police, fire or EMS have access to them quickly when they call for help," the Douglas County Sheriff's Office wrote on Facebook.
An Apple representative declined comment.