Here's the blog post from twitter on the announcement. [
blog.twitter.com...]
This is going to be helpful. According to the announcement, it's rolling out now, and should be to all users in the coming weeks. Additionally, there's going to be more control coming later, too.
Users that are subject to abuse will welcome this greatly, and it's not always the users you may think. Youngsters are the most vulnerable, and I can see it helping them. Some outspoken with their views often get abuse for just daring to voice an opinion, and others just get spammers. This, i'm sure, will help combat the problems many feel were out of control.