Dave Grohl's ready to Foo Fight some Swifites ... 'cause he took a shot at Taylor Swift -- implying she's not actually performing live at her shows.
Dave Portnoy Defends Taylor Swift After Dave Grohl's Apparent Jab
Dave Portnoy is a big fan of Dave Grohl ... but he can't wrap his head around why the Foo Fighters frontman would pick a fight with..
TMZ.com