Siri, the voice command system on the iPhone 4S, is being blocked on IBM's internal networks, the company's CIO has revealed. Jeanette Horan mentioned the fact in an interview with MIT's Technology Review this week. The core issue involves the way Siri translates speech; rather than performing the task on a phone, it uploads recordings to Apple servers, where the speech is deciphered before results are sent back. Accompanying this is user data, such as the names of people in Contacts, since the information is needed to interpret some requests.