Advocacy is an activity by an individual or group which aims to influence decisions within political, economic, and social systems and institutions. Advocacy can include many activities that a person or organization undertakes including media campaigns, public speaking, commissioning and publishing research or conducting exit poll or the filing of an amicus brief. Lobbying (often by lobby groups) is a form of advocacy where a direct approach is made to legislators on an issue which plays a significant role in modern politics. Research has started to address how advocacy groups in the U.S. and Canada are using social media to facilitate civic engagement and collective action.