I saw this on the T's Red line a few weeks ago. Usually graffiti I see is vulgar or simply misplaced vanity "Paul wuz here". In this case there was a clear bit of protest and counter point. I don't know why, but I found this really compelling. It seemed so perversely civilized.
The text appeared to be written by two separate authors.
Author 1: "Pharma [SIC] only cares about profits everything else is secondary"
Author 2: "Fortunately, profits are good at motivating them to cure diseases like this kids."