An Australian senator has come up with a cunning plan to stop phone scammers: any call from an unregistered VoIP line should show the caller's number as “666”.

Senator Pauline Hanson detailed the idea in a letter to communications minister Mitch Fifield, as part of a government review into dealing with scams.

On Facebook, she explained what she's asking of the minister:

“International persons are able to buy what appears to be a local, domestic phone number, with commonly recognised prefixes.

“Those with mobile phones and digital display fixed landlines, are unsuspecting of scam calls when these prefixes appear on the screen and are left vulnerable to often convincing scammers.”

The post continues: “Senator Hanson proposed that all incoming calls to Australia, from non-registered VOIP lines or virtual numbers, should be assigned with a prefix of ‘666’ and then followed by a pre-recorded message warning 'This is an overseas call. Please be aware of phone scams from numbers you do not recognise'.”

VoIP calls display an Australian number if the caller has signed with a service provider offering local numbers; someone using SkypeOut (for example) without buying a PSTN number will present as a private number.

Since Senator Hanson hasn't provided technical detail for her proposal, The Register suggests reviving and modifying RFC 3514, “The Security Flag in the IP v4 Header”:

“[W]e define a security flag, known as the "evil" bit, in the IPv4 [RFC791] header. Benign packets have this bit set to 0; those that are used for an attack will have the bit set to 1.” ®