FBI taps cell phone mic as eavesdropping tool

http://news.com.com/FBI+taps+cell+phone+mic+as+eavesdropping+tool/2100-1029_3-6140191.html

The FBI appears to have begun using a novel form of electronic surveillance in criminal investigations: remotely activating a mobile phone’s microphone and using it to eavesdrop on nearby conversations.

how useful is this, really?  have you ever gotten a call from someone’s cellphone when they leave the keypad unlocked and their ass decides to call you?  it sounds like a mashup of turntablism and satinism…