I'm not directly involved with ProxyKey, but I know that fraud is not tolerated on the service. ProxyKey clients are typically marketing agencies that use IP's to check advertising, etc.. from different locations. The closest it comes to being shady is craigslist clients who use it to post in cities in which craigslist wouldn't otherwise let them because they are more than a certain distance away. The proxies only have web ports open, so email is not allowed along with any other type of scamming/fraud.