Two citations from Malhotra et al. (2004) [1] come to my mind here: First, "any act of data collection […] is the starting point of various information privacy

Two citations from Malhotra et al. (2004) [1] come to my mind here: First, "any act of data collection […] is the starting point of various information privacy concerns” (p. 338). Second, privacy can be defined as “the degree to which a person is concerned about the amount of individual-specific data possessed by others relative to the value of benefits received” (p. 338) This explains why we are so sensitive if random people take pictures of us, without our consent. Usually, there is nothing we can gain, but a lot to loose, under some circumstances. In Social Media, it is necessary to acknowledge both sides of the trade - users also gain something, which is why they/we are more willingly to give up some part of their/our privacy. This is also the case, to some degree, in public street surveillance. It is not the case, however, in random street photography. [1] Malhotra, N.K.; Kim, S.S.; Agarwal, J. Internet users’ information privacy concerns (IUIPC): The construct, the scale, and a causal model. Inf. Syst. Res. 2004, 15, 336–355.