by which they investigate people they've met offline”. Connections formed online sometimes are transformed to off-line personal relationships. Parks and Floyd (1996) report that 60% of their random sample “reported that they had formed a personal relationship of some kind with someone they had first contacted through a newsgroup”, and that “relationships that begin on line rarely stay there”. Privacy issues are commonly reported in popular media. According to Gross and Acquisti (2005), “many individuals in a person’s online extended network would hardly be defined as actual friends by that person; in fact many may be complete strangers. And yet, personal and often sensitive information is freely and publicly provided.” Therefore, users potentially expose themselves to physical and cyber risks. Influences on social capital Internet usage can cause multiple effects for social capital, and its effects are not yet clear. For example, Pigg & Crank (2004) suggest that studies of relationship between online networks and social capital is still too much in their infancy to reach any useful conclusions. Although it is generally thought that Internet affects social capital, “mechanisms are unclear” (Hampton, Wellman, 1999). Internet usage can both increase and decrease social capital: “people engage in social and asocial activities when online” (Hampton, Wellman, 1999). For example, Nie (2001) claims that social capital can be decreased: “Internet use may actually reduce interpersonal interaction and communication”. He also claims, that “Internet users do not become more sociable; rather, they already display a higher degree of social connectivity and participation”. Hampton, Wellman (1999) claims, that “increased connectivity and involvement not only can expose people to more contact and more information, it can reduce commitment to community”, because “immersiveness can turn people away from community”. Some researchers claim that social capital can be increased by Internet usage. For example, Ellison, Heino, & Gibbs (2006) claim that “Internet facilitates new connections, in that it provides people with an alternative way to connect with others who share their interests or relational goals”. Hampton, Wellman (1999) state that Internet supplements network capital “by extending existing levels of face-to-face and telephone contact.” Reduction of communication costs increase the frequency and duration of communication, and increase social capital's bonding and bridging. The Net is particularly suited to the development of multiple weak ties (Castells, 1999), thus expanding sociability beyond the socially defined boundaries of self-recognition. Internet supports weak ties between individuals, which can the foundation for bridging