Twitter Starts Blocking Users Who Post Abusive/Harassing Tweets.

In a bid to stop trolling and online harassment, Twitter has now begun to reduce the reach of abusive accounts. The social media site's new vetting system temporarily restricts the tweets of abusive users, making them effectively invisible to those who don't already follow them.
As well as stopping them being retweeted outside of their inner circle, this measure also works with mentions too. If the offending user tries to tweet at someone who isn't following them, for example, the intended receiver now won't get any notifications.

While this certainly isn't the first measure Twitter has taken against abusive behaviour, this latest step reinforces the company's commitment to cracking down on harassment. Predictably, some users aren't particularly happy about the new system. Since the new measures were implemented last week, one person has insisted that his account was restricted simply for using a word that Twitter deemed unacceptable. The social media giant, however, states that it looks at an account's behavior rather than simply just restricting people based on abusive language.
Source ; Buzzfeed