How to Avoid an Internet Call Being Tracedby Robert Schrader
When you use an Internet application to make a phone call, the phone number that appears on the recipient's caller ID isn't always a number he can use to call you back or identify you. It may be still be possible to trace any call you make to you, so don't use the false anonymity of Internet calling to make inappropriate or harassing phone calls.
How Internet Calling Works
Internet calling works using voice over IP or "VoIP" technology, which transforms analog audio signal such as voices during a phone call into digital data to be sent over Internet connections. This digital data can be sent to other computers to make computer-to-computer calls or transmitted wirelessly to cellular and landline phones, at which point it's transformed back into an analog audio signal. The VoIP process isn't a direct exchange like an ordinary telephone call, which means that although a phone number displays on the recipient's caller ID, it may not allow him to get back in contact with the caller.
Skype is a prominent VOiP application. After downloading a free software application onto his computer or smartphone, a registered Skype user can make voice calls to cellphones and landlines without ever picking up a phone. Unless the Skype user has signed for a custom Skype phone number, an unassigned phone number based in the U.K. displays on the recipient's caller ID, one that has no correlation with the Skype user's account.
Google Voice operates differently. Unlike with Skype, whose users must pay a premium to have phone numbers at which others can call them, all Google Voice accounts have virtual "phone numbers" that display on the caller IDs of the people they call. Calling someone's Google Voice number rings through to devices on which the person uses Google Voice, or, if none are available, to the cellphone number he used to register with Google Voice. You can't block your Google Voice phone number when you make a call using the service.
Harassment and Recourse
Even with a service like Skype, which seems to conceal your identity completely, you shouldn't use the Internet to make harassing or malicious calls. If the person you call has to get local authorities involved, he may be able to subpoena Skype or whichever other service has provided technology for the calls to get your screen name or other identifying information and subsequently take action.