U.S. Rep. Alexandria Ocasio-Cortez D-NY., and actor Mark Ruffalo are among those who have taken to Twitter to criticize Elon Musk's potential plan to charge users $8 a month for identity verification and what it means for free speech.

On Friday, Ocasio-Cortez asked Musk "why should people pay $8 just for their app to get bricked when they say something you don’t like?" She also shared a screenshot of her Twitter notifications under the "verified" tab appearing blank.

"This is what my app has looked like ever since my tweet upset you yesterday," she wrote. "What's good? Doesn't seem very free speechy to me."

Actor Mark Ruffalo retweeted AOC's post, asking Musk to "get off Twitter."

"Hand the keys over to someone who does this as an actual job, and get on with running Tesla and SpaceX," he wrote. "You are destroying your credibility. It’s just not a good look."

"Hot take: not everything AOC says is 100 accurate," Musk responded.

The actor also retweeted AOC's tweet last week criticizing the $8 a month subscription plan, saying it's bad for advertising.

"As we are the products of Twitter, those blue checks make advertisers feel more comfortable putting their brands next to those verified accounts," he wrote Friday. "Without those verified accounts, bye bye ad buys. This thing doesn’t run without advertising."

After criticizing the subscription plan Friday, Ruffalo tagged Musk in a retweet of an article on the climate crisis minutes later asking him to focus on "what really matters."

"As the richest man in the world and owner of this platform, use your power and privilege to address this REAL threat," he wrote. "I remember when this was paramount to you. Elon, come back to your original purpose."

"This isn’t the time for pettiness but greatness. Use your gifts & this platform for good information, not misinformation & cruelty," the actor tweeted.

This article was originally published on NBCNews.com