Reduce the damage done by retweeting and dogpiling. Simply navigate to a user's followers/following page and activate the extension by clicking the icon next to the omnibox/address bar. The extension does not block users you are following, or re-block users that have already been blocked. You can also export and import lists of followers in a special format. If an abusive user has blocked you, you can use the export function to retrieve the list of their followers/followings after logging out, and then import the result after logging back in to Twitter.
View blocking receipts and add protected users by right clicking the extension's icon and choosing "Options."
Please report issues on GitHub: https://github.com/satsukitv/twitter-block-chain/issues
Source available here: https://github.com/satsukitv/twitter-block-chain