sacrilege

sacrilege \SAK-ruh-lij\, noun:
an intentional injury to anything held sacred; disrespectful treatment of something sacred
A big, catchy ad on Page One of the print edition would be considered sacrilege. The editorial staff wouldn't stand for it and anyone who bought it would come in for loud criticism from purist.
-- William Spain, MarketWatch, 3/28/2003
San Francisco's Finest: In this town, it's sacrilege to attempt naming the "top" restaurant.
-- Los Angeles Times
c 1300, from Old French sacrilege, from Latin sacrilegium and sacrilegus "one who steals sacred things," from sacer "sacred" + legere "take, pick up." Transferred sense of "profanation of anything held sacred" is attested from 1390.