Cool stuff. Back in the day, I worked for a website hosting company and was tasked with finding several of our major competitor's customers. I chose a more rud

Cool stuff. Back in the day, I worked for a website hosting company and was tasked with finding several of our major competitor's customers. I chose a more rudimentary route than this - which was to convert the huge lists of hostnames to their IP addresses. Everything in our world then utilized shared hosting, so a relatively small list of IP addresses would map. We then would proceed to scrape the sites for emails, phone numbers. Which was easy because our competitors had standard templates for their clients.