Typically, if someone from a payphone dials a tollfree number, that number is hit with a significant connection fee--maybe 50 cents give or take? I have no idea if that's different for Canadian payphones. The issue with blocking Canada is that inbound calls from Canada are 7c/min, but from the US are 5c/min (or so). Now that cell phones are so prevalent, it seems much less important to allow inbound calls from payphones, but thinking of the however improbably 'emergency situation,' like a teenager who doesn't keep her cellphone charged is driving alone on a rural highway, car dies, she walks to a gas station, finds a payphone... :-D

The problem, as I see it from what I think is Tim's perspective (he can correct me if needed) is that the following scenario is much more probable: someone steals a credit card number, sets up a tollfree number that allows inbound tollfree from payphones, sets up quite the 'business'... repeats cycle with new card each time the current one gets discovered and blocked... Meanwhile, voipo is eating those costs (or even if the bank is, voipo has to deal with all the associated hassles)...