Twitter's General Council has said it's taken action against a number of accounts it beleives have violated its terms of service. It appears the accounts were suspended not long back in an earlier purge, and then opened new accounts. Those new accounts indicated to twitter suspicious behaviour and having multiple accounts have now been suspended.
Users are more likely to be asked to confirm a phone number, making it easier to identify as a duplicate.
Another action we take is to suspend accounts that we catch violating our rules, which also removes them from follower counts. While it may be hard to see follower counts go down, these actions are making Twitter a better place for everyone.