A necessary change to Twitter's reply system

Twitter's reply system needs work. The most obvious need for improvement is the placement of replies. Twitter needs to allow users to control what shows up under our tweets. If I block a troll who is posting obscene things, I do not see the troll's tweets under mine. But the reply is still there, so anyone else who views my tweet will see the obscene tweet under mine.

Other social networks do not work like this. If I post something on Facebook or Google Plus and someone replies with obscene language, I can delete the comment and no one sees it. Obviously, I cannot delete a tweet posted by someone else. That is a good thing. But there is no way to prevent obscene tweets from appearing under mine.

So the solution is simple: Make the blocking feature more robust. If I block someone now, he cannot follow me, reply to me or even see my tweets, but his existing replies are still visible to everyone else. If I block someone, his replies should not be visible to anyone. The tweet would not be deleted, of course, but someone would either need to go directly to the URL or to the troll's profile to see it.

It is strange that this has never been fixed, especially with Twitter's alleged commitment to fighting abuse and harassment on its platform. If someone is being harassed by trolls, there is no way to hide all of the abusive and obscene tweets under his tweets, even if he has blocked the trolls. The only way to hide the replies is to delete the tweets the trolls replied to. Twitter users should not have to engage in self-censorship to remove abusive replies on their own profiles.