I hope by "intercepted", you mean "they noticed it and disarmed it" and not "it blew up on them instead of us".
But, the fact that they made such devices and that they do work is enough cause for concern that such a thing could be done over here.
Now, a "truck packed with them" would be rather easy to spot... but I wonder just how much havoc one could cause if someone put one in a garbage can or somewhere similar where it'd hit a bunch of people...
But as stated earlier in the thread, the phones were supposedly trafficked... that would make sense, buying a phone with a plan is $100 or more, but they sell them for $20-30 at Wal-Mart, but those are programmed to use Tracphone's service... I suppose if you could "jailbreak" the phone and get it to work with normal wireless service... well, they could make some decent cash off of that.
Not sure why the propane tanks were stolen though....