Over the weekend, Twitter users noticed they were suddenly following the official Twitter account of the President of the United States, against their will. On Sunday, the social network’s CEO Jack Dorsey apologized.

Dorsey took to Twitter addressing the issue. He explained that a problem occurred after the social media platform was migrating users from the previous @POTUS account to the new one. Dorsey revealed over 500,000 accounts became affected following the migration.

Dorsey stated that the Obama administration worked on creating a transition plan for the 45th President of the United States. But, because @POTUS is not a personal account, the Obama administration felt that they should transition accounts with followers but have the new @Potus account have 0 tweets.

Jack Dorsey emphasized that the transition started at 12PM on January 20th. The plan was as follows, “If you were following @ POTUS before 12p ET, by end of day, you’d be following *two* accounts: @ POTUS44 (44th Admin) and @ POTUS (45th Admin),” Dorsey explained.

But, two problems occurred. The first problem was that people who followed @POTUS44 were also set to follow @POTUS. People who unfollowed @POTUS in the past were now following @POTUS.

“We believe this affected about 560,000 people. This was a mistake, it wasn’t right, we own it, and we apologize. No excuses,” Dorsey said.

All: we investigated what happened here, and we made some mistakes (which have been corrected). Some context first. https://t.co/W1n3Xs6LaN — jack (@jack) January 21, 2017

Twitter during the election

Launched was launched in 2006 by Jack Dorsey, Noah Glass, Biz Stone and Evan Williams. The Twitter app gained in popularity and by 2012, the social network had more than 100 million users with over 340 million tweets a day. According to a New York Times report, Twitter was the biggest social media mover and shaker during election day 2016. In fact, there were more than 27,000 posts every minute by 11 a.m.

Despite Twitter’s extreme popularity during the election, Twitter has struggled to make a profit. Consequently, the company announced a plan to lay off 9% of their staff; this resulted in the end of Twitter’s social video app Vine, which officially shut down earlier this month.