Investors are expected to play an active role in ensuring corporate good governance. Sometimes they interfere, even without actually holding shares, like giant ABP in the recent Stork Case. What exactly does drive institutional shareholders to engage in shareholder activities? A review of the literature on this issue poses a number of interesting questions. Is shareholder activism always directed at creating a positive effect on the value of the stock? Or do shareholders also intervene in an attempt to comply with societal, normative and ethical expectations?