WhatsApp Messenger is a cross-platform instant messaging client for smartphones, PCs and tablets. The app relies on the Internet to send images, texts, documents, audio and video messages to other users that have the app installed on their devices. Launched in January 2010, WhatsApp Inc. was acquired by Facebook on February 19, 2004, for about $19.3 billion. Today, more than 1 billion people use the service to communicate with their friends, loved ones and even customers.
Excessive use of digital technology, like social media, by adolescents can cause disruptions in their physical and mental health, in sleeping patterns, their weight and levels of exercise and notably in their academic performance. Research has continued to demonstrate that long hours spent on mobile devices have shown a positive relationship with an increase in teenagers' BMI and a lack of physical activity. Moreover, excessive internet usage has been linked to lower grades compared to users who don't spend an excessive amount of time online, even with a control over age, gender, race, parent education and personal contentment factors that may affect the study. In a recent study, it was found that time spent on Facebook has a strong negative relationship with overall GPA. The use of multiple social media platforms is more strongly associated with depression and anxiety among young adults than time spent online. The analysis showed that people who reported using the most platforms (7 to 11) had more than three times the risk of depression and anxiety than people who used the fewest (0 to 2). Social media addiction and its sub-dimensions have a high positive correlation. The more the participants are addicted to social media, the less satisfied they are with life.
Social media often features in political struggles to control public perception and online activity. In some countries, Internet police or secret police monitor or control citizens' use of social media. For example, in 2013 some social media was banned in Turkey after the Taksim Gezi Park protests. Both Twitter and YouTube were temporarily suspended in the country by a court's decision. A new law, passed by Turkish Parliament, has granted immunity to Telecommunications Directorate (TİB) personnel. The TİB was also given the authority to block access to specific websites without the need for a court order. Yet TİB's 2014 blocking of Twitter was ruled by the constitutional court to violate free speech. More recently, in the 2014 Thai coup d'état, the public was explicitly instructed not to 'share' or 'like' dissenting views on social media or face prison. In July of that same year, in response to WikiLeaks' release of a secret suppression order made by the Victorian Supreme Court, media lawyers were quoted in the Australian media to the effect that "anyone who tweets a link to the Wikileaks report, posts it on Facebook, or shares it in any way online could also face charges".
Social media are interactive computer-mediated technologies that facilitate the creation and sharing of information, ideas, career interests and other forms of expression via virtual communities and networks. The variety of stand-alone and built-in social media services currently available introduces challenges of definition; however, there are some common features: