Can’t GPS or someother tracking practice follow his everymove? They could find him at Camp David or where he travels at any place or time. I don’t know how terrorists set off bombs thru cellphones, but I would not want to be carrying one at anytime. If they can’t do that now, I am sure they will figure it out.
Yup.
The tracking is easy, unless his particular Blackberry has been rigged to eliminate the GPS function (Secret Service would probably insist on that). Even then, it could still be loosely tracked through cell tower triangulation, but that's not as precise.
Terrorists have used cell phones to set off bombs, but they can't make the cell phone itself explode unless they can rig it with explosives. Then again, I'm not sure that terrorists would have any reason to harm an ally.
There are two separate channels involved in making cell phone technology work. One is the channel you are actually communicating on, and the other is a "maintenance" channel that allows the device to negotiate with various cell phone towers for the best connection and bandwidth.
To ensure interoperability among the various carriers, from the infancy of the technology the "maintenance" channel was designed as essentially wide open, not secured, and not capable of being secured.
For this reason, there are several "hacks," widely available to every interested hacker, from the sophisticated threats to the 14 year old "wannabees" in Mom's basement; that allow you to remotely turn on a cell phone and use it as a remote listening device.
Turning off the cell phone does not defeat the hacks. You will never have any indication that your cell phone was on and was used in this manner, except for possibly a drained battery.
This is the reason behind the "No Cell Phones" rule in secured spaces, and why the little compartments you lock the phones in outside the secure spaces are essentially Faraday cages.
The use of the "maintenance"channel bypasses any logging or security mechanism built into the communications channel, significantly reducing the audit and forensics footprint, and the threat of discovery and prosecution of the hacker.
The only time you cell phone is not susceptible is if it is off, with the battery removed, and not connected to some other power source.
With two BlackBerries, Obama is essentially walking around with two bugging and recording devices that are throughly PWN3D by up to 200 different foreign intelligence collection threats. There only problem will be the competition with the other 800,000 or so threats capable of using the same technology, limited by the power and bandwidth of the devices. His only protection is that they will probably create a perpetual Distributed Denial of Service (DDOS) attack against him.
To quote that sage observer of human incompetence, Bugs Bunny: "What a maroon!"