Twitter DM: Make It Usable

Twitter (Photo credit: Wikipedia)
Twitter’s Small Chance To Maim Email

There is one feature that would make me use Twitter's Direct Message service, the Twitter feature I ignore the most right now. It is that yes, it is good only people I follow should be able to DM me. But I want a feature where if someone sends me a DM I don't like, I can block them from DMing me in the future, but I don't have to stop following them on the public Twitter.

This is a small request to make. But I don't see Twitter acting on it.