There is a free service that works with all voip phones such as Vonage (which I use). It is called NOMOROBO. I just registered and installed it about a week ago and it works beautifully. Your phone has to have the simultaneous ring function. When a call comes in that is on the robo call list, it will ring on your phone and at the nomorobo call center simultaneously. After the first ring, if the call is a known robo caller, the call center will answer and hang up immediately killing the call. If you encounter a robo caller that still gets through, you just report the number and it is now on the list. I can still see all the numbers on caller ID just in case it blocks a call I wanted. I reported one that still got through a few days ago and now it does not get through because I can still see who calls on caller ID which is carried on the first ring. I am on the national and state DO NOT CALL list, and have reregistered on that, but it is simply not working very well anymore. I really do love this service and it is free. When my phone rings just once, I know that I was saved the headache of a robo caller. It is still not a totally perfect method because there are ways around it like using new numbers all the time, but I think that it is as perfect as it gets for the moment.