Also, interesting thing, ToS says: Your use of Firefox must follow Mozilla’s Acceptable Use Policy
and that link for Acceptable Use Policy is talking about mozilla services only.
So is Firefox now a service?
in that case:
- (you are forbidden to) Upload, download, transmit, display, or grant access to content that includes graphic depictions of sexuality or violence,
therefore you are forbidden not just to watch porn through firefox, but even to watch some of shady youtube ADs 