Earlier quoted context omitted.
Since I can't seem to convince you, here's a definition of "Derivative Work" straight from 17 U.S.C. 101 ( https://www.law.cornell.edu/uscode/text/17/101 ) (emphasis mine). (FWIW, I am a licensed attorney who specialized in IP law while in law school; this is not legal advice.) "A “derivative work” is a work _based upon one or more preexisting works_, such as a translation, musical arrangement, dramatization, fiction…
I don't consider the Facebook logo itself to embody a level of unique creative expression sufficient to qualify as an artwork. Obviously, if contested, that decision could be overruled by a judge, but I like my chances there. .-----. | .-| Probably does not | -+-| violate copyright. | | | '-----'
You'd be better off arguing some other angle, but please study law first so as not to waste anyone's time.