Dust Sails

I came across a few references to the idea of a light
sail composed of dust in a plasma, but all of the references I
can find seem to be from the same small group of people. Are
dust sails so recent an idea as not to attracted much discussion
yet or is there an obvious flaw to the idea?
--
"I mean, you don't seem like a bad guy to me..."
"I don't? I got a death touch, an army of killer robots and a skull
drawn on my chest and I don't look like a bad guy to you? I think
you could be in the wrong business."