On Thursday, President Donald Trump’s personal lawyer and confidant, Rudy Giuliani, was locked out of his Twitter account for a brief period of time after posting a Ukrainian official’s phone number.

A Twitter spokesperson told The Verge that Giuliani’s tweets, which included screenshots of text conversations with Andriy Yermak, violated the platform’s rules on posting private information. Those screenshots did not censor Yermak’s phone number, essentially doxxing the Ukrainian official to Giuliani’s followers.

At roughly 3:40PM ET, Giuliani told Fox News reporter John Roberts that his account had been locked, although he resumed tweeting shortly afterward. In accordance with Twitter policy, Giuliani’s account would have remained locked until the offending tweet was removed.

An adviser to Ukrainian president Volodymyr Zelensky, Yermak has found himself at the center of a growing scandal concerning Giuliani’s efforts to dig up scandals on former Vice President Joe Biden. Last month, a whistleblower filed a complaint over concerns that Trump used his office’s power to encourage Zelensky to investigate potential foreign dealings between Ukraine and 2020 Democratic presidential contender Joe Biden’s family. The whistleblower’s complaint repeatedly mentions both Attorney General Bill Barr and Giuliani. Ever since its disclosure, Giuliani has been filling his Twitter feed with text message screenshots with Ukrainian officials and himself in an attempt to deny any criminal actions.

The scandal has tested the limits of Twitter’s rules on a number of occasions. Several Democratic presidential candidates have called on Twitter to ban President Trump in response to apparent calls for retaliation against the whistleblower. Thus far, Twitter has declined to take any action on the requests. More recently, the president ran afoul of the platform’s intellectual property system, when one of Trump’s tweets casting doubts on Biden’s activities in Ukraine was removed for using an unlicensed Nickelback song.