https://www.techdirt.com/articles/20200814/14125345112/content-moderation-case-study-twitter-acts-to-remove-accounts-violating-terms-service-buying-selling-engagement-march-2018.shtml

Summary: After an investigation by BuzzFeed uncovered several accounts trafficking in paid access to "decks" -- Tweetdeck accounts from which buyers could mass-retweet their own tweets to make them go "viral" -- Twitter acted to shut down the abusive accounts.

Most of the accounts were run by teens who leveraged the tools provided by Twitter-owned Tweetdeck to provide mass exposure to tweets for paying customers. Until Twitter acted, users who saw their tweets go viral under other users' names tried to police the problem by naming paid accounts and putting them on blocklists.