This study approaches online social networking from the opposite direction, focusing on unsociability, in an attempt to find out how friendships are negotiated and terminated online. The research data was obtained via an online survey (N=107) targeted to SNS users. The findings show that Facebook is closely connected to offline social life, and the fading of offline relationship was the most common reason for cutting ties on Facebook. Usually, the people who were unfriended represented weak ties. Even though unfriending can be considered as the hardest form of unsociability, it was more commonly used than restricting content from certain people. On Twitter and other SNSs, the relationships were less personal. Therefore, ‘unfollow’, ‘block’ and other unsocial features were used to filter and regulate the content subscribed to. Particularly on Facebook, attention should be paid to developing affordances that would enable the system to better match the dynamic and complex nature of social relationships.