Siri has a lot of useful functions, but is thwarting kidnap one of them? Well, no, probably not, but if you ask Siri to "charge my phone 100 percent" then it automatically starts calling the emergency services, giving you a 5-second window to cancel the call. We're not sure exactly why this happens — it could just be a bug, of course — but one consequence is that it could be used in some sort of home invasion scenario, allowing someone to secretly call the police without attracting attention.

While this sounds like a far-fetched scenario, it's not beyond the realms of possibility. Earlier this year, for example, a woman used Pizza Hut's app to alert the police that she and her children were being held hostage by a boyfriend with a knife. Asking a kidnapper if you can charge your phone with some weird passphrase is pretty innocuous by comparison. However, there's no official mention from Apple of this "function," and the only evidence of its use online is a scattering of tweets going back to early July of teens trying to prank one another with it. At least that's a believable use case.

However, we should note the obvious: don't mess around with this. Calling the emergency services "for fun" is dumb, wastes resources, and could end up with a cop at your front door.

Update July 16th, 9:10AM ET: Readers have pointed out that Siri might just be reacting to the instruction "phone" followed by any number. The command "Siri, charge my phone 911 percent" also dials the emergency services, while using other percentages (e.g. "Siri, charge my phone 560 percent") simply result in Siri trying to call that number.

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