As part of Twitter’s plight to improve the safety of its subscribers, new users will be prevented from registering accounts with the phone numbers of known trolls (people who deliberately provoke others online to create discord). Steps have also been put in place to make it easier for users to report harassment on the network. The moves come after a memo by CEO Dick Costolo that calls for "kicking these people off right and left" in order to prevent online abuse, and comes on the heels of an initiative from last year that began to allow bystanders to report abuse. That same approach is now being taken for instances of self-harm, impersonation, and the publishing of private information.