Del Harvey, head of trust and safety at Twitter, has said that the company's policy is: "We don't want people to use our platform to do things that are illegal that's not something that we support."
"I think a lot of times people think that we stand on the whole 'Twitter is a platform for free speech - so anything goes' and that's just not the case," she said.
"We do have policies against a lot of harassment ... and a threat of rape or violence is not something that's protected by that sort of concept of anything goes."
More top news
Speaking to ITV News' Mark Austin on the anniversary of the London bombings, ex-PM says nations around the world will need to respond.
A Canadian man has been arrested after tying more than 100 balloons to a garden chair and flying over the city of Calgary.
A van bearing the faces of some of Britain's most wanted fugitives will be driven around parts of Spain popular with expats in a new push.