Harassment is one of the biggest problems facing Twitter right now. Some of the company's most popular and influential users have been driven off the platform because of some truly horrific, hurtful tweets. The problem hasn't gone unnoticed. Twitter has promised to do more to combat trolls, making it simpler to flag abusive tweets and banning controversial figures such as the conservative writer Milo Yiannopoulos. Now, according to Bloomberg, it's working on a keyword filtering system that would allow users to hide tweets containing specific terms and phrases. If you've muted keywords before on TweetDeck or Tweetbot, you'll get the idea.