Jessica Guynn

USA TODAY

SAN FRANCISCO — Fairly or not, Twitter is known the Internet over as the place the trolls are.

Stung by criticism that Twitter has allowed harassment and abuse to spread unchecked and under growing pressure from Wall Street to deliver growth, CEO Jack Dorsey has pledged "a completely new approach to abuse." Twitter's vice president of engineering Ed Ho said last week the company will keep working on combating abuse "until we’ve made a significant impact that people can feel."

The pledges have been met with skepticism from critics. Twitter is out to prove that it's taking safety on the platform seriously with a new set of updates that begin rolling out Tuesday. The changes will give users more control over what they see on the social media service, Twitter says.

Chief among them: preventing people who have been permanently suspended from Twitter from creating new accounts, focusing in particular on accounts that are created "only to abuse and harass others," Ho said in a blog post.

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"Safe search" results are being turned on for users. These results remove tweets that contain sensitive content such as violent or pornographic images or language or tweets that come from blocked or muted accounts. And Twitter is working to identify and "collapse" potentially abusive and "low quality" replies to tweets.

"We stand for freedom of expression and people being able to see all sides of any topic. That’s put in jeopardy when abuse and harassment stifle and silence those voices. We won’t tolerate it and we’re launching new efforts to stop it," Ho said.

This is the second safety update that Twitter has rolled out in little more than a week. Twitter said last week that users can now report tweets that mention them even if the user has blocked them. Officials say to expect more safety updates in coming weeks.

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The reason for the flurry of updates? Abuse has taken a sharp toll on Twitter, which reports fourth-quarter financial results on Thursday. Walt Disney Co. decided not to pursue a bid for Twitter, partly out of concern about bullying on the service. The lack of interest from potential acquirers cranked up pressure on Twitter management, which has fallen out of favor with Wall Street.

The service known for its 140-character messages has struggled to broaden its mainstream appeal and bring in advertising dollars while the fortunes of established competitors such as Facebook have soared and newer entrants such as Snapchat and Facebook-owned Instagram have quickly gained traction. Snapchat, the messaging service run by Los Angeles company Snap, is on the verge of an initial public offering that could raise billions and bring a heady valuation.

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Twitter, on the other hand, is being forced to retrench, discontinuing its Vine mobile app and coming off a second round of cuts after it let go 8% of its workforce a year ago. The money-losing company has said it's targeting profitability in 2017.

For years, Twitter billed itself as "the free speech wing of the free speech party." But as it grew, that hands-off approach contributed to a dramatic rise in abuse, harassment and hate speech.

People don’t have to use their real names on Twitter. And with that anonymity has come racist, sexist and anti-Semitic taunts and even full-fledged campaigns from trolls, prompting the temporary departures of high-profile users such as Ghostbusters actress Leslie Jones.

As the company's user and revenue growth stagnated and public backlash increased, Twitter has in recent months begun to address complaints. But after a bitterly divisive election, personal attacks and threats have only escalated.

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Former CEO Dick Costolo recently expressed regret for not working aggressively to eradicate abuse on Twitter years ago.

"I wish I could turn back the clock and go back to 2010 and stop abuse on the platform by creating a very specific bar for how to behave on the platform," he said last week during the Upfront Summit in Los Angeles. "I take responsibility for not taking the bull by the horns."

Dorsey now seems determined to take the bull by the horns. Last year, Twitter improved its abuse reporting system and convened outside advisers on safety issues.

In November, Twitter took steps to crack down on hate speech, from making it easier to report alleged incidents to educating moderators on what kind of conduct violates the rules. Twitter users also gained the ability to mute words and phrases, even entire conversations, if they don't want to receive notifications about them.