The raise of social Web brought new ways of disseminating information, news and published content over the Web. Social news aggregator Web sites such as Digg and Reddit are already known for their role in promoting user-based content by utilizing story submission and voting system. Balatarin, the first and one of the most famous news aggregator in Persian language, is a social bookmarking Web site, which is developed by combining the underlying idea of Reddit, Digg, Newsvine and Del.icio.us. Although Balatarin is among popular and influential Web sites in the Middle East, there has not been any analytical research on it. Here, we studied the user activity to see whether it is dominated by few users' participation, or social incidents can motivate users and influence their contribution. For our study, we collected data representing user activity over the course of three years. We carried out some computational analysis on user participation under social circumstances, such as blockade and election in Iran. The evaluation of the results shows that such social factors can motivate users to break the tyranny of the minority submitters by contributing more.