You would think that no one would be more vested in diabetes treatment or prevention (through applied science, not lifestyle change) than Coke. You would think that no one would be more vested in cancer research than tobacco companies.
On an unrelated note, the pictures of the wiped away or whitewashed logos on buildings made me sad on a strange level. Sure, its just marketing. But for communities, they could be reminders of bygone eras and in many cases the driving force behind the community itself. I recognize that behind all of that is a for profit corporation of potentially many outside people reaping the benefits of the community. Still, it seemed a bit like wiping away the past.
I work for a very large financial institution and we give locally to many charities - to the tune of several $million just in my city alone. Sometimes the community notices, many times it doesn't. If anything though, it endears the employees to the company a little more. I'm not sure I would consider working at a firm that did nothing for its community, especially considering the advantage it has of being able to withdraw from the community at will. My company could also be considered an "activist" when compared to our peers, good or bad. The activism has to be a two-way street, though and I think it works for my company because they attempt to bring together many stakeholders to the table with their efforts - to be fair, it works most of the time but some of the effort falls flat.
I think the reason the Bandcamp example works so well is that Bandcamp and the interests of all stakeholders, customers included, appear to be aligned. The BP example doesn't sit so well because clearly that is not the case. BP doesn't have to be inherently evil for their campaign to be ineffective or ill-conceived by our standards - I feel that their campaign simply leaves out all necessary stakeholders. BP also has exponentially more complicated problems to deal with so maybe not such a fair comparison.