Twitter(TWTR)CEO Dick Costolo has made it a personal mission to stop bullying and abuse on the microblogging service.

The head of the social media company told employees recently that "trolls" on the platform undercut its business. He also took it on himself to solve the problem. 

"I take PERSONAL responsibility for our failure to deal with this as a company," he wrote in a memo obtained by The Verge, ". . . It's nobody's fault but mine."

A balance
Like any service based on a community of users expressing ideas, thoughts, and opinions, Twitter has a problem in that free speech is not always pretty. The challenge for Costolo is maintaining a platform in which people can freely express themselves while stopping trolls -- people who attempt to get a rise out of others by starting arguments, making outrageous statements, and generally sowing discord.

The documents published by The Verge showed an exchange between Adrian Cole, a Twitter employee, and Costolo, which was posted on an internal message board.

Cole: I'm aware that Twitter is well within its rights to let its platform be used as a vehicle for sexist and racist harassment. But, as a private company -- just like a comedian mulling over a rape joke, or a troll looking for a target for his anger -- it could choose not to. As a collective of human beings, it could choose to be better. 

Costolo: . . . I'm frankly ashamed of how poorly we've dealt with this issue during my tenure as CEO. It's absurd. There's no excuse for it. I take full responsibility for not being more aggressive on this front. It's nobody else's fault but mine, and it's embarrassing.

We're going to start kicking these people off right and left and making sure that when they issue their ridiculous attacks, nobody hears them.

We suck at dealing with abuse and trolls on the platform and we've sucked at it for years. It's no secret and the rest of the world talks about it every day. We lose core user after core user by not addressing simple trolling issues that they face every day.

For Costolo, while having his brand perceived this way is a problem, it is also an opportunity. If he can police the service better and make it a safer, troll-free environment without clamping down on legitimate expression, he could make his struggling social media site more attractive to advertisers.  

Steps are being taken
While Costolo is only now standing up and taking personal responsibility, he has not been blind to the problem.

In December 2014, Twitter released an improved process for reporting abuse on the site that was designed to streamline the nine-step system previously used. The changes allow people who are not directly involved in the abuse to flag it more easily, while also giving users a page where they can view and edit the users whom they have previously blocked. At the same time, the new rules prevent blocked users from viewing the profiles of the people who blocked them. 

These moves might have helped, but they have not solved the problem -- abuse and trolling remain an issue on the platform, as Costolo acknowledged. 

This might be holding the company back
Twitter has grown into the second largest social network in the United States, behind Facebook(META 2.98%), but it has struggled to generate revenue, and growth has sputtered. In its most recent quarter, the company increased revenue to $479 million, up 97% year-over-year, but it lost $578 million for the period and only added 4 million new users.

Those numbers are not terrible, but they are well behind the growth delivered by Facebook. And, while trolls are only one of the problems Twitter faces, establishing an abuse-free platform would likely make it more attractive to users and advertisers.

It can be fixed
Twitter must tread carefully on this issue to err on the side of free speech. But the company would be well within its rights to strengthen blocking tools -- so a user can say whatever he or she wants, but another user can opt out of seeing it. In addition, the company should also make it as easy as possible for anyone to report abuse when a physical threat is made. 

Costolo has stepped up and made this his priority. This is a difficult problem, but it can be fixed. If he succeeds, Twitter not only becomes a better place to visit but also a stronger business.