Adding sulfuric acid to iron creates an exothermic reaction which produces iron sulfate and hydrogen gas, a nasty mixture, but only in the presence of water. If you mix undiluted sulfuric acid directly with iron, depending on humidity you might get a mild reaction due to moisture content in the air.
Anyway, for years people have used Fe as a tag online to indicate irony ('cause iron). Adding H2SO4 is my way to making it sarcasm 
