Caroline Criado Perez said it was "great" that Twitter had taken a "first step" in dealing with harassment on the social media site, but said more needed to be done.
Ms Criado Perez, from north London, was one of a number of women who were subjected to a torrent of abuse by Twitter users last month.
Ms Criado Perez said: "It's great that Twitter has listened.
"There are still issues: users have to agree for the report to be potentially shared with the harasser, and there are some boxes that could be auto-populated that aren't. But overall, this is a fantastic first step."
More top news
Chelsea won the first domestic trophy of the season thanks to a 2-0 win over London rivals Spurs at Wembley.
An online video showing a naked man apparently falling down the outside of Buckingham Palace has split opinion online - is it a hoax?
A new market has started up in London championing the production of sustainably produced, local food.