Indeedy - designing contact systems that are incentively-aligned to cater for genuine communication while also preserving privacy and discouraging spam/scams.. seems like a tricky problem. NB: The sample URL in my comment should have read: `http://james.<webtel>` (james dot angle-bracketed-webtel) to make it more clearly an invalid link, while still demonstrating the idea - my mistake for not factoring-in the HTML filtering.