Twitter is used by a substantial minority of the populations of many countries to share short messages, sometimes including images. Nevertheless, despite some research into specific images, such as selfies, and a few news stories about specific tweeted photographs, little is known about the types of images that are routinely shared. In response, this article reports a content analysis of random samples of 800 images tweeted from the UK or USA during a week at the end of 2014. Although most images were photographs, a substantial minority were hybrid or layered image forms: phone screenshots, collages, captioned pictures, and pictures of text messages. About half were primarily of one or more people, including 10 % that were selfies, but a wide variety of other things were also pictured. Some of the images were for advertising or to share a joke but in most cases the purpose of the tweet seemed to be to share the minutiae of daily lives, performing the function of chat or gossip, sometimes in innovative ways.

In social media, people often press a “Like ” button to indicate their shared interest in a particular content or to acknowledge the user who posted the content. Such activities form relationships and networks among people, raising interesting questions about their unique characteristics and implications. However, little research has investigated such Likes as a main study focus. To address this lack of understanding, based on a theoretical framework, we present an analysis of the structural, influential, and contextual aspects of Like activities from the test datasets of 20 million users and their 2 billion Like activities in Instagram. Our study results first highlight that Like activities and networks increase exponentially, and are formed and developed by one’s friends and many random users. Second, we observe that five other essential Instagram elements influence the number of Likes to different extents, but following others will not necessarily increase the number of Likes that one receives. Third, we explore the relationship between LDA-based topics and Likes, characterize two user groups—specialists and generalists—and show that specialists tend to receive more Likes and promote themselves more than generalists. We finally discuss theoretical and practical implications and future research directions.

ABSTRACT Children's online privacy has garnered much attention in media, legislation, and industry. Adults are concerned that children may not adequately protect themselves online. However, relatively little discussion has focused on the privacy breaches that may occur to children at the hands of others, namely, their parents and relatives. When adults post information online, they may reveal personal information about their children to other people, online services, data brokers, or surveillant authorities. This information can be gathered in an automated fashion and then linked with other online and offline sources, creating detailed profiles which can be continually enhanced throughout the children's lives. In this paper, we conduct a study to see how widespread these behaviors are among adults on Facebook and Instagram. We use a number of methods. Firstly, we automate a process to examine 2,383 adult users on Facebook for evidence of children in their public photo albums. Using the associated comments in combination with publicly available voter registration records, we are able to infer children's names, faces, birth dates, and addresses. Secondly, in order to understand what additional information is available to Facebook and the users' friends, we survey 357 adult Facebook users about their behaviors and attitudes with regard to posting their children's information online. Thirdly, we analyze 1,089 users on Instagram to infer facts about their children. Finally, we make recommendations for privacy-conscious parents and suggest an interface change through which Facebook can nudge parents towards better stewardship of their children's privacy.