The Black Keys star Patrick Carney has reignited his war of words with Justin Bieber, taking aim at the Baby singer for turning his 40 million Twitter followers on him last year (13). The drummer became a target for Bieber's 'Beliebers' after the pop singer suggested Carney "should be slapped" for an off-hand remark he made that he meant as a compliment. The Lonely Boy hitmaker told TMZ.com that Bieber shouldn't be too upset about not winning a Grammy Award in 2013 because he's making so much money. The young star took offence and tweeted, "The Black Keys drummer should be slapped around haha," triggering a massive online feud between fans of the two acts. And now Carney has revisited the spat in a new interview with Rolling Stone, telling the publication, "Justin Bieber, like a f**king irresponsible a**hole, sicced 40 million Twitter followers on me because I paid him a compliment he didn't understand. "I'm saying that he should be grateful that he has a f**king career in music. And he shouldn't be f**king telling his followers to slap me, and then also be doing anti-bullying bulls**t. It's so irresponsible. He adds, "Justin Bieber is a f**king moron. And that's the gist of what I was saying. And then he goes and says I should be slapped? Honestly, I feel bad for him... I don't dislike his music. I don't listen to his music, but he needs to not conduct himself that way."