I think that we have many people that like to read what people have to say but do not like putting their name to a point of view for what ever reason but would participate in a anonymous tick box , there for contributing where they would not have before , and as long as each member can only click once on each post then I don't see how it could be abused or be abusive to any one , so I would have thought it can only be a good thing or at worst do no harm to any one ,
The other thing is that if it was found to be un wanted for what ever reason it could be removed just like that so no real harm to any one , just more work for Malcolm setting it up (and I would have no idea how difficult that would or would not be ) and as I said as long as members could only tick once on each post I don't see how it could be abused , so has my vote for inclusion