Mark Ruffalo has waded into Ellen DeGeneres' controversy over her friendship with George W Bush, saying the former US president must be "brought to justice".
The talk show host explained her unlikely friendship with Bush after the pair were seen at an NFL game together, despite his history of trying to limit gay rights and other actions that appear at odds with her views.
"I'm friends with a lot of people who don't share the same beliefs that I have," DeGeneres said on her show Ellen this week.
"When I say be kind to everyone, I don't mean be kind to the people who think the same way you do. I mean be kind to everyone."
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Many social media users have criticised her message, but Ruffalo is one of the only fellow celebrities to publicly denounce it.
The Avengers: Endgame star took to Twitter to call DeGeneres out.
"Sorry, until George W Bush is brought to justice for the crimes of the Iraq War, (including American-lead torture, Iraqi deaths & displacement, and the deep scars - emotional and otherwise - inflicted on our military that served his folly), we can't even begin to talk about kindness," he said.
Ruffalo's public scolding of DeGeneres is being celebrated by many on social media, while other celebrities are being criticised for expressing the opposite view.
Reese Witherspoon and Kristen Bell both supported DeGeneres's comments online - although Witherspoon later deleted hers - leading to accusations of their "privileged" way of looking at the circumstances.
"There are thousands of people in the Middle East who don't get to be friends with people with 'different views' because they're dead, thanks to him," tweeted a LGBTQ media advisor.
"And he spent his presidency trying to strip away LGBT rights, so nah. This monologue is pure class privilege."
"Bomb a million people, go to baseball game with celebrities imploring everyone to be kind to people you 'disagree with'," added business owner Shiung Low.
"Go get a manicure with Stalin while you're at it. Why not 'be kind to those you disagree with' after all."
Of course, other fans supported Witherspoon, Bell and DeGeneres. And while many applauded Rufflo's message, some took issue with it.
"Yes, the person you should all be piling on right now is ELLEN DEGENERES for going to a football game you absolute f**king lunatics," tweeted writer and comedian Bridget Phetasy.
DeGeneres has not responded to Ruffalo, nor spoken out about the reaction to her on-air comments.