We have some computers that are available for public use. The computers themselves are set to not remember browsing history and when the user ends their session, it reverts the HDD back to a 'base image' erasing all files and changes (for customer privacy).
On the network side, we have a pfsense-based firewall and OpenDNS for web filtering.
The other day, we had a report that somehow a public user was viewing child pornography that was somehow posted on a Craigslist ad. OpenDNS didn't stop it because Craigslist isn't blocked. He left the computer (which erased all the local data) and the OpenDNS logs only said that craigslist.org was accessed by our external IP.
Is there a way that I can remotely send browsing logs to another computer? How should I have had things set up to record that information? If we start recording it, do we need to notify our customers that they're being monitored?