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
Planning on going to the London Marathon tomorrow? Read our handy guide first!
Celebrations to mark St George's Day have started in Trafalgar Square with feasts and tea to be found in abundance.
People took to the streets of Brixton today to march against what they see as the 'gentrification' of the area.