The outspoken rapper, 44, had some super-harsh words for Bowling for Columbine director Michael Moore and The Interview star Seth Rogen, who've both publicly criticized Clint Eastwood's latest film about real-life Navy SEAL sniper Chris Kyle's life on and off the battlefield.
"F*ck you Michael Moore, you're a piece of s*it and your uncle would be ashamed of you," he wrote on his website, referring to Moore's claim that his uncle was killed by a sniper in World War II, and that snipers were "cowards."
My uncle killed by sniper in WW2. We were taught snipers were cowards. Will shoot u in the back. Snipers aren't heroes. And invaders r worse
He also went in on Rogen, who tweeted that the film reminded him of a fake Nazi propaganda film in Inglorious Basterds.
"Seth Rogen, your uncle probably molested you," the "Cowboy" singer wrote. "I hope both of you catch a fist to the face soon."
Rogen wasted no time in his comeback, tweeting, "And what's super weird is that @KidRock IS my uncle."
Interestingly enough, Rogen has already backtracked on his original comments, but further clarified his initial tweet in a lengthy post on Thursday.
"People claimed that I compared the movie American Sniper to Nazi propaganda, something I would NEVER do ... and also implied that I somehow have something against Chris Kyle and veterans in general, neither of which are true to say the least," he wrote. "My comment about the movie was not meant to have any political implications. ... I'm sorry if this somehow offended anyone, but that was not my intention."
On Thursday, ET spoke with retired Navy SEAL Kevin Lacz, who served with Chris Kyle, and played himself in American Sniper. Watch the video below to see hear Lacz's thoughts on all the recent controversy, as well as how Bradley Cooper convinced him to be in the Oscar-nominated film.