title: Collect logs and analytics while maintaining user anonymity?
body: <p>Say I'm running some sort of public web service and I'd obviously like to collect metrics. For the sake of this argument, let's assume the data I'm interested in would only be what is available from parsing standard Apache access logs. Is there a way to maintain these types of analytics without also keeping identifying information about users?</p>
  
  <p>I've thought about things like hashing IP addresses but this has many obvious problems.</p>