Okay - but both craigslist/ebay already have "protection" built in. They each have a proxy type of contact system already - craigslist even has a "roller" system if you will - the email.
If you learned tomorrow that craigslist had created exactly the same service and then added it to their ads, what then?
If you learned tomorrow that craigslist had created exactly the same service and then added it to their ads, what then?