Twitter suspended the account of President Donald Trump's longtime associate Roger Stone this weekend following a series of derogatory and threatening tweets from Stone to CNN personalities.
Stone said he plans to file an antitrust lawsuit against Twitter, according to Business Insider.
Following a report from CNN that a grand jury approved the first charges in former FBI Director Robert Mueller's special counsel investigation, Stone sent irate messages to CNN anchor Don Lemon and contributor Ana Navarro, among others.
After the tweets, Stone's account was suspended. He said on Facebook that he was told he was under temporary suspension, but had learned from press accounts that Twitter is banning him permanently.
Twitter declined to comment on "individual accounts."
The company's policy states suspension can occur in response to threats or harassment.
Stone has known Trump for decades and is a reliable supporter of his political movement. He has also frequently used his platform to go after reporters and those critical of him and the President, Friday's insults being the latest example.
For his part, Stone seemed to relish the attention the suspension got, writing, "I guess you have really arrived when your brief suspension on Twitter is national news."
Stone's suspension comes more than a year after another high-profile Trump supporter, Milo Yiannopoulos, was banned from Twitter. Yiannopoulos was seen as an instigator of disparaging tweets directed at comedian Leslie Jones.
Yiannopoulos, a self-described provocateur, is known for making offensive statements and railing against "political correctness."
Twitter has grappled with how to police its platform for years. Like other social media sites, its critics say, the company has struggled to strike the right balance between allowing free speech and tamping down harassment and hate speech. Earlier this month, Twitter CEO Jack Dorsey laid out new measures aimed at preventing the latter.
The new policies came after an outcry over the brief suspension of actress Rose McGowan's account. Twitter says she was temporarily booted from the platform for violating policies against publishing private phone numbers. But the suspension came as McGowan was a leading voice among women speaking out against Harvey Weinstein, the disgraced movie mogul whom McGowan accused of rape. Weinstein denies any accusations of sexual assault.
Many Twitter users decried the decision to suspend McGowan and sparked the widely used hashtag #WomenBoycottTwitter.