This is thought to be Apple's new feature that allows iOS users to immediately dial 911 emergency call numbers during an emergency. Pressing the power button five times in a row on iOS 11 will bring up the option to make a phone call to the emergency number.
Additionally for some users, performing these actions also disables the Touch ID and locks the device, until the user enters the correct lock code. The ability is assessed as a form of Apple's reaction to the outrage delivered by President Trump through his Twitter account.
Delivered through his Twitter account last year, President Trump criticized Apple for not being cooperative when law enforcement agencies asked for help to open iPhone 5c access to terrorism and murder in San Bernardino, California.
Tim Cook previously expressed concern that to meet government demand, Apple must create a new version of iOS potentially will be exploited by the perpetrators of crime and threaten the security of iPhone users.
The incident was a terror attack and the FBI could finally unlock the iPhone 5c belonging to a terrorist without help from Apple. However, the device reportedly contained no information that could help in the course of the investigation.
Now, more than a year later, Apple is trying to prevent law enforcement agencies from accessing their work phones without the user's permission, thanks to a feature called cop button or police button.