"That same month, Meta Pixel also deployed a new method that used WebRTC, a real-time peer-to-peer communication protocol commonly used for making audio or video calls in the browser. This method used a complicated process known as SDP munging, a technique for JavaScript code to modify Session Description Protocol data before it’s sent. Still in use today, the SDP munging by Meta Pixel inserts key _fbp cookie content into fields meant for connection information. ..."