A change may be socially desirable, but bringing about change requires costly action and enough people taking such action — creating a classic collective action problem. We study whether access to similar information about the desirability of change helps people to mobilize for a shared goal. Similar information allows people to coordinate better, but it can also exacerbate the free-riding problem. We propose a natural order of interdependence of information structures and show that more interdependence helps (hurts) when bringing about change is hard (easy). We apply this theory to several examples such as protests, boycotts, and reporting workplace misconduct.