1. A computer-implemented method of building a social network based on content in images, the method comprising: using, at least one processor, to identify a first person in an electronic image; identifying a second person related to the electronic image; creating first social network information relating the first person to the second person; storing, in a storage device, the first social network information; identifying second social network information relating the first person with a third person; and creating third social network information relating the second person to the third person based on the relation of the second person to the first person in the first social network information and the relation of the third person to the first person in the second social network information.