Firefox update v57.0 has forced youtube into HD mode on my desktop. This is chomping up my data at an alarming speed. Considering I only have 25gb per month this will be gone in a few days. I need SD mode back. I know there used to be youtube settings to throttle the data usage on desktop but they disappeared a long time ago. I cannot force youtube to turn off auto video selection, it keeps re-sizing the video from small into larger HD mode. I have tested Microsoft Edge and Internet Explorer and they are unchanged, youtube is still being played in SD mode. So its not youtube, its firefox. Help!