The rise of network-based, automated services in the past decade has definitely changed the way businesses operate, but not always for the better. Offering services, conducting transactions and moving data on the Web opens new opportunities, but many CTOs and CIOs are more concerned with the risks. Like the rulers of medieval cities, they've adopted a siege mentality, building walls to keep the bad guys out. It makes for a secure perimeter, but hampers the flow of commerce. Fortunately, some corporations are beginning to rethink how they provide security, so that interactions wit