Found a great resource with details, ideas, and info, on what is going on with these scammers. Lifted this from 800Notes.com:
>> If you want to stop these calls then you need to dry up their revenue source. Your phone company is charging you a fee for caller ID. Your phone company pays the scammer for sending their caller ID information. Your phone company pays only a fraction of a cent per call and you pay $5 to $15 to your phone company. The scammers send out millions of calls per day which amounts to a significant amount of money however your phone company is charging a large amount to millions of customers. This may have something to do with the phone companies inability to stop these calls. You can also see why the criminals keep calling even though they know you won't fall for their scam. If someone does make the mistake of answering the phone and falling for their con then it is just icing on the cake for them. These people are the lowest form of filth on this planet.
In order to stop this we need legislation making it illegal to charge for caller ID. If a phone service wishes to operate it would need to provide the caller ID at no charge to other phone providers and to it's customers as part of the service. Here is the $50,000 solution that the FCC is looking for and it doesn't cost anything.
Many of the disposable numbers come from Pacific Telecom Communications Group and they are currently under investigation and in the midst of various lawsuits. (The principles involved have been part of actions by the FCC under other business names). Here is an excellent blog site that I found that explains how this company is getting away with this activity.
Read through at the link, and it seems as if the state AG's are having better luck closing off these scumbuckets.