Other social media sites have been doing it. Do we want to join in?
EDIT: Some people are saying that this is a power that ought to be left to communities… do we have a specific delineation of powers that relegates these decisions to communities? If not, then I recommend that these users propose such a delineation of powers. I would be very ok with this proposal failing because instead we got a more explicit set of checks and balances.
This however will lead to easier spread of fake screenshots. These are common for Twitter, so checking the source easily is valuable for verification.
Which is why links should always be there. No matter how shit a site may be, a link to the original source for authenticity should always exist.