Gunmen in the Mumbai attacks tried to avoid their communications being tapped by using a US Voice over IP service.

According to Network World, one of the terrorists spoke to his Pakistani handler using a virtual phone number provided by service provider Call Phonex. This virtual number was used to contact a mobile telephone with one of the terrorists. However, the conversation was intercepted and all calls made through the virtual number were also intercepted and recorded.

Network World was uncertain if the authorities monitored the call via a tap on the wired portion of the network or by eavesdropping on the wireless leg of the connection. However, it is unusual for Voice over IP companies to be involved in wiretapping operations.

Call Phonex issues phone numbers from 35 countries so that when the the numbers are dialled within those countries, there are no toll charges. The terrorist's handlers could call the him using a local Pakistan number, and be connected via Call Phonex’s network to the terrorist’s mobile.

The account was opened by someone using the name Kharak Singh, who identified himself as being in India. It was paid for by a Western Union transfer from Pakistan under the name Mohammed Ashfaq.

Earlier reports said that the gunmen used Indian mobile phones to talk to their controllers. X