Dick Costolo, Twitter CEO
Dick Costolo has acknowledged Twitter’s shortcomings in dealing with cyberbullyingReuters

Twitter CEO Dick Costolo has said the social media network "sucks" at dealing with trolls and it is driving users away.

A leaked memo picked up by technology publication The Verge showed an exchange on an internal forum in which one employee highlights a recent quote from Lindy West on the This American Life podcast that points out the company could do more.

In a frank reply, Costolo acknowledged how poorly Twitter performs in dealing with cyberbullying, and said he was "ashamed" and took responsibility for the company's failings.

Costolo said: "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.

"I'm frankly ashamed of how poorly we've dealt with this issue during my tenure as CEO.

"I take full responsibility for not being more aggressive on this front. It's nobody else's fault but mine and it's embarrassing."

Costolo then sent a follow-up message reiterating his point.

"We HAVE to be able to tell each other the truth, and the truth that everybody in the world knows is that we have not effectively dealt with this problem even remotely to the degree we should have by now, and that's on me and nobody else," he said.

"So now we're going to fix it, and I'm going to take full responsibility for making sure that the people working night and day on this have the resources they need to address the issue, that there are clear lines of responsibility and accountability, and that we don't equivocate in our decisions and choices."

Internet trolls have been a cause for concern for several years now with commentators pointing out the need to eradicate them.

The case of Brenda Leyland in 2014 has been one of the most high-profile cases in recent times. The 63-year old was found dead in a hotel room after she had been exposed for trolling the parents of Madeleine McCann on Twitter.

Leyland was condemned by the British media after it was revealed that she had sent "thousands" of abusive tweets to Kate and Gerry McCann.

A few days after a tense exchange on Sky News in which the broadcaster confronted her about her online activities, Leyland was found dead in a hotel room. An inquest into her death is currently ongoing.