The issue is with the encryption that BBs use, which prevents snooping on the traffic. Kicking anyone sending encrypted data off the network would be a good way

The issue is with the encryption that BBs use, which prevents snooping on the traffic. Kicking anyone sending encrypted data off the network would be a good way to do that. As I understand it, the data is relayed through RIM's servers on the way to corporate networks as well, so blocking them would probably also factor in. The cellular networks also probably have some way to identify devices, though I'm not certain of this. Failing that, arresting anyone who tries to get into the country with a blackberry would probably work pretty well.