VoIP is currently getting a lot of folks excited, but some bodies in the security world fear that it comes with some security risks. The Voice over IP security alliance (VoIPSA) claims that there are a whole host of security difficulties that could potentially cause problems for organisations.
There are problems like privacy and eavesdropping, harassment by phone, premium rate abuse, and hijacking of service, all of which are common to VoIP and PSTN.
Newer threats invlude VoIP spam, caller-ID impersonation, denial of service attacks, authentication and complex ID fraud.