The voip insider blog has a great article about Craigslist and VoIP.

Craigslist is using a calling system to help reduce their fraud. In a nutshell, basically they call you and give you a code. When you enter the code back into their website, they are happy and allow you to post on their website.

Well, the system they use to reduce fraud is automatically assuming numbers listed with VoIP carrier companies such as Level3 are fraud. Level3 happens to be one of the largest VoIP carriers in the world; handling traffic for almost every major VoIP company.

So, if you were happy with your new VoIP provider and ported your number, would Craigslist still assume you were a bad person?

With all of the people switching to VoIP service, we’re sure this oversight will be corrected shortly.