In 2004, Lee Holloway and I started Project Honey Pot. The site, which tracks online fraud and abuse, primarily consists of web pages that report the reputation of IP addresses.
We generate a lot of logs. To give you some sense, across the CloudFlare network every minute we write a half a Gigabyte of just log data. Collecting, reducing, sorting, and displaying that data back to you is one of the biggest challenges of running a service like CloudFlare.