I read, don't remember where, that the Israelis have rigged up a number of phones this way. They would be harmless to you and me because we are not terrorists. But terrorists like this dog are kept under constant surveillance, and when he makes use of one of the phones, then the phone is manually detonated. Definitely done under manual control - blowing someone's head off with C4 is not yet left to a voice recognition circuit. Only the Palis would do it that way.
By the way, this whole exploding phone thing started when the Israelis managed to get an exploding cell-phone in a bad-boy's hands. After he was dispatched the terrorists switched to pay phones.
This seems gruesome, but it is line with the Israeli policy of targeting individuals, rather than repeatedly killing women and children on buses and in restaurants. Gotta love those Israelis. I sure want them on our side in the next war - they, like we, are the good guys.
Good guys with a sense of humor, if your gonna fight these scumbags you might as well have fun.