https://www.theguardian.com/technology/2018/jul/11/twitter-follower-counts-locked-accounts-fake-news

Locked accounts will be removed from follower numbers, as company targets spread of abuse and misinformation

Twitter users will see a drop in their follower counts this week as the company clamps down on “problematic” accounts including those that have been hijacked to spread abuse, misinformation and propaganda.