On a Blackberry model 8830, when the keyboard is locked, and the trackball is pressed twice within a few seconds, a menu titled "Handheld is locked" is displayed which offers three options:
- Emergency Call
While in this mode, if the trackball is moved and pressed again, which could occur accidentally while being carried in a holster or pocket, it is possible that set of events can place an emergency 911 call.
According to Blackberry tech support support, there is no way to directly disable this feature, or change the emergency number called.
A workaround is to set the Blackberry into Standby mode, by pressing the Mute key on top of the phone near its right edge. This is easier than having to use the Keyboard Lock icon in the main menu, and fully locks the keys on the phone, yet allows incoming calls to be received, much like when the keyboard is locked. To manually bring the phone out of Standby mode, press the Mute key again.
Since the Mute key is recessed, unlike the trackball, it is unlikely that using Standby to lock the keyboard will be accidentally undone.