Twitter is starting to take harassment seriously. And while we haven’t always seen eye to eye with the company on some of their strategies, we think their newest effort deserves praise. We've pointed out that companies like Twitter aren’t very good when it comes to policing content—but users should have control over what they see. Last Wednesday, Twitter announced that it is adding the ability to share their block lists:

You can now export and share your block lists with people in your community facing similar issues or import another user’s list into your own account and block multiple accounts all at once, instead of blocking them individually.

While Twitter’s implementation has room for improvement (more on that below), we think this is a step in the right direction. We hope more platforms will recognize that giving control to users is an important, overlooked (although not comprehensive) way to address harassment. Twitter explains that the new tool works by allowing users to create .csv files of block lists. These files can be manually shared with other users, who can import them. Once a file is imported, everyone on that list is blocked, but users can manually unblock individuals.

Users should be aware that, in comparison to tools like Block Together, this is a static tool. Other tools work as a subscription service; once a user subscribes to someone else’s list, they automatically get updates from that person’s list. If the creator of a block list adds a new person, that person is automatically blocked for every subscriber. And if the creator decides to unblock someone, that person's account is removed from every subscriber's block list too. With the Twitter tool, once a file is imported, even if the person you originally imported it from decides they made a mistake, you’ll never know. If you want to know who they have blocked most recently, you’ll have to ask. Finally, if you want to get their block list, you’ll also have to ask them for the list directly—sharing lists isn’t automatic with the Twitter tool.

While we believe that block lists can be an effective tool against harassment, allowing users more control and companies less, they are not without problems. Just as these tools can be used to block serial harassers, they can also be misused by, for example, political types to block their opponents. The challenges with block lists increase if they mutate from a feature that individual users can tweak themselves, into a preset default that lacks transparency or feedback mechanisms.

In the early days of combating spam, EFF and others pointed out the dangers of centralized blacklists, and we continue to have concerns when users aren't aware of blocking mechanisms and cannot easily reconfigure how their communications are being filtered. Every user should have complete control over what they say and hear online. The more direct and fine-grained that control is, the better it is for free speech. Lack of control is best addressed by empowering end-users to make their own decisions, and creating a diverse community of developers who can create tools customized to individual needs.

That brings us to one other piece of Twitter’s announcement that deserves mention. The announcement specifically noted that Twitter is “working on additional user controls.” While it would be great for Twitter to continue to build these tools, the announcement also noted “We also hope these advanced blocking tools will prove useful to the developer community to further improve users’ experience.” So do we.