What is Mobile Business Social Network

New information and communication technologies and their integration extend the possibilities for people for high level collaboration independently where they are on the globe. Various groups of people can come together according to their private or business interest forming a virtual community (VC) through online social networks. Beside the positive effects of this technical breakthrough there are dangerous sides of using these high level networked systems; the personal data of the individuals can be used by other persons especially when the individual doesn’t take care of them. So, privacy has now an increasingly important role in social networked environments. As trust is the base of the society there is close connection between trust and privacy. The goal of this paper is to present the role and relationships between trust and privacy in mobile (business) social networks, and to introduce the possible types of privacy threats and countermeasures in case of online social networks. A short summary on future trends in mobile social networks is also presented.