Twitter is taking more steps to fight abuse and harassment on its service, unveiling new efforts Tuesday that include preventing repeat offenders from being able to create new accounts.

The new changes aimed at curbing personal attacks and abusive behavior on Twitter — which CEO Jack Dorsey has said is a top priority for the company — will also include removing potentially offensive tweets from search results, and graying-out potentially abusive or low-quality tweets.

The most significant move is that Twitter will now begin to identify people or organizations that have been permanently suspended and stop them from creating new accounts. Critics will wonder why Twitter, which launched in 2006, hasn’t put such a measure in place until now — given that bad actors have been a nagging problem nearly since the short-message service’s inception.

The steps to block chronic abusers “focuses more effectively on some of the most prevalent and damaging forms of behavior, particularly accounts that are created only to abuse and harass others,” Ed Ho, Twitter’s VP of engineering, wrote in a blog post announcing the changes.

Last November, Twitter introduced new ways to fight trolls, including letting users “mute” notifications based on keywords, phrases, and conversations, and last week it launched an improvement to how users can report abusive tweets.

As part of the new efforts announced Tuesday, Twitter said it is working on a “safe search” feature, which removes tweets that contain potentially sensitive content and tweets from blocked and muted accounts from search results. “While this type of content will be discoverable if you want to find it, it won’t clutter search results any longer,” Ho wrote.

Twitter also is developing ways to identify and “collapse” potentially abusive and low-quality replies in users’ notifications (although all tweet replies will still be accessible if you want to read them).

The troll problem for Twitter has reached embarrassing lows in recent months. Most notably, actress Leslie Jones (of “Saturday Night Live” and “Ghostbusters”) last summer was attacked with racist tweets, prompting her to temporarily abandon the service. That led Dorsey to personally intervene, and Twitter subsequently banned conservative agitator Milo Yiannopoulos and other accounts over the abusive incidents.

The company says it’s not done with its anti-harassment campaign. “In the days and weeks ahead, we will continue to roll out product changes – some changes will be visible and some less so – and will update you on progress every step of the way,” according to Ho.

As of the end of September, it had 317 million active monthly users, and making Twitter a safer place is clearly critical for the company to retain existing users and attract new ones. Twitter is scheduled to report fourth-quarter 2016 earnings on Thursday morning.