Steemit - We need a 'donate' button (as well as a 'promote' button) where any money made from a post gets automatically donated to a charitable cause

There seems to be a good number of people on Steemit who aren't just motivated by personal financial gain.  

They often want any Steem Dollars that are made from a post to be given to a charity.

An addition of a donate button at the bottom of an article (pressed by the author) would indicate to the Steemit community that any proceeds of this post would be donated.

With a change in the Steemit system (similar to the Null account which gets money from a posts promotion) after the payment time has elapsed any Steemit Dollars made would be automatically sent to a 'Charity Null' account.

The Steemit community together could then vote at regular intervals on which charity this 'Charity Null' accounts money is sent onto.

I feel this would stimulate more philanthropy in the Steemit system and provide a shared system based way of impacting the wider world.

Any thoughts?