Twitter’s (NYSE: TWTR) most recent accounts purge has taken a big bite out of the follower numbers of some of the biggest accounts on its site. The purge, undertaken as an effort to clean up the social media platform, was expected to impact many of the accounts on the platform as it went on through the week. In a statement, Twitter said that “most” people would lose “four followers or fewer,” but that the most prominent Twitter accounts “will experience a more significant drop.”

A long list of celebrities, politicians, social media stars and news organizations saw their followers drop as part of Twitter’s purge. The main New York Times account lost about 730,000 followers, while CNN’s breaking news account lost roughly 1 million. President Donald Trump’s personal account saw more than 200,000 of its 53 million followers disappear. Microsoft cofounder and philanthropist Bill Gates lost nearly 900,000 followers.

Several of the most popular Twitter accounts lost millions of followers. Katy Perry, Justin Bieber, and Barack Obama are the three most popular Twitter accounts, with 110 million, 107 million, and 104 million followers respectively before the purge. The singers each lost nearly three million followers, while Obama lost more than 2 million followers.

Television stars Oprah Winfrey, Ellen DeGeneres and Kim Kardashian West lost more than a million followers each. Basketball star LeBron James saw his follower count fall by 880,000. About 900,000 followers were purged from global soccer superstar Cristiano Ronaldo’s account.

The biggest loser in the purge by far was Twitter’s own account. The purge resulted in the deletion of more than 12 percent of its followers, or about 7.8 million users. Twitter CEO Jack Dorsey lost 200,000 followers, according to a tweet he posted.

The large numbers of followers disappearing in the accounts purge brings into question the prevalence of bots and spam accounts on the platform. While it has been found that numerous Twitter users rely on bogus accounts and bots to inflate their follower count, Twitter has estimated that spam or troll accounts make up only a small fraction of its users. The company says that most of the accounts being purged are accounts that were locked following suspicious changes in behavior.