From Sci(entologist) + -fag.
scifag (plural scifags)
- (Internet slang, derogatory) A Scientologist.
2008 February 9, barb, “Re: scifag to anonfags: don't do this "for Lisa"”, in alt.religion.scientology[1] (Usenet):Thanks for playing, scifag.
EPIC FAIL!
2008 October 19, stop-scientology [username], “Melbourne, Australia, october 18, 2008: Anon protest against the cultof Scientology”, in alt.religion.scientology[2] (Usenet):There were a couple of elderly scifags sitting opposite the State Library at one stage.
2009 June 9, Pisces [username], “Re: IRA vet seeks black blotter”, in alt.drugs.hard[3] (Usenet):So you are a scifag trying to make those who post against scifags look like crazy fuckers.