I highly recommend Eric Ries' new book Incorruptible if you want to learn more about this stuff. In there he tells the story of the Vectura Group, a pharma company that was developing treatments for asthma and other respiratory diseases. It was looking at a sale, and it had a couple offers, the one from Phillip Morris slightly edged out the other, and because of fiduciary duty, even though many involved viscerally hated the idea of going to Phillip Morris, as the cause of many of the ailments they sought to cure, they sold to them.