Twitter has outlined three changes it's implementing to deal with abuse and harassment on the platform. First, it wants to make bans more effective by doing what it can to prevent people from making new accounts. It says it'll take steps "to identify people who have been permanently suspended."
The network is also changing its search results so that potentially "sensitive content" is removed by default. You can still locate those tweets if you like, but they won't be immediately displayed.
A similar step is being taken with replies. Twitter will identify and collapse "potentially abusive and low-quality replies" so that users initially see the most relevant ones. Again, you can find the rest if you want to.