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."
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A cloudy start to the short Christmas week. It's gong to be a mild one though with temperatures already above the double figure mark.
As we move into a shorter working week for most people, we are looking at a generally cloudy one.
Lots of cloud around today feeling relatively mild although it probably felt a bit cooler because of the breeze.