The blog post doesn't go into detail, but apparently a banned user may have to offer up a phone number to Twitter to start using the service again. While it's a stronger move against trolls, the official blog posts stops short of saying it'll ban repeat offenders outright. The company told the Washington Post it's now tripled the size of the team that works with users who have been abused. These changes start rolling out today, and will spread to all users in the next few weeks.