Why is Twitter tracking people’s phone numbers?

Weeks after The Verge published internal memos from Twitter CEO Dick Costolo in which he said “we suck at dealing with abuse,” the company is rolling out new tools to reduce harassment on the service. Under the changes, users who receive temporary bans may have to verify an email address or a phone number to resume using Twitter. (Other users can be banned permanently.) Email addresses are relatively easy to obtain, but phone numbers are harder — and by checking phone numbers against a list of banned users, Twitter could be able to keep more abusers and harassers from creating accounts. In December, Twitter improved the workflow for reporting abuse and harassment, making it easier to do on mobile devices and requiring fewer inputs. For the first time, it also allowed bystanders, rather than the victims themselves, to report abuse. With today’s update, Twitter is bringing the same tools to reporting impersonation, self-harm, and the inappropriate posting of personal information. Now third-party accounts can report those violations of Twitter’s terms of service using the same simplified workflow.