This paper discusses how to add privacy features to the Janus WebRTC media server and gateway. In order to do so, we embrace a standard approach, by leveraging work currently ongoing within the IETF PERC working group. PERC stands for Privacy Enhanced RTP Conferencing and is aimed at enabling centralized real-time conferencing in a scenario where the central media forwarding entity is not required to be trusted by any of the conference participants. The paper analyzes the impact of the integration of double encryption, which is part of the PERC efforts, both on the Janus core and on the plugins it provides for WebRTC streams management and manipulation.