Good find. I did some quick googling on this (so take it a grain of salt) and found the following:

 A breach of fiduciary duty occurs in a variety of situations, such as when the fiduciary puts his own interests before the company and shareholders or when the fiduciary engages in other behavior that could be detrimental to the company and shareholder interests, such as embezzling company funds.  

I have not dug too deeply, but what little I’ve found says that the fiduciary must act in the best interests of the company and shareholders. As a cynic it is easy to interpret this to mean ‘make as much profit as possible’, which is kind of the point of investing. A look back at history sadly reenforces this.

But fiduciary duty doesn’t give one a free pass to break other laws like child labor or slavery. Yes many companies still do as evidenced by sweatshops around the world. But if one is acting in the best interests of the company, one should not be doing such things even though they are obviously profitable.