The Role of HTTPS Inspection in Google Search and YouTube Reports
Since Google made the decision to implement HTTPS across all their web properties (including YouTube), you can report that someone has been to youtube.com, but not what videos they were watching. Likewise, you can report that someone has visited google.com, but not what they searched for. Fortunately, many Next Gen Firewalls, UTMs and Secure Web Gateways have a HTTPS Inspection feature that gets around this problem.