People are social to begin with, and those that gravitate to all sorts of social media platforms, such as Instagram, Facebook, and Twitter, do so as a matter of course of staying in touch with family and friends, amongst other things, such as news, and whatever else piques their interest. In addition, younger people, in general are far less circumspect in how public they are in discussing their lives, in regards to what they post and comment upon, for younger people are typically far more fearless than those that are older, of which, to advertisers and collectors of data, younger people are exceptionally valuable, especially if they can be marketed to, directly or indirectly.
It would be one thing, if social media platforms, were really about what they claim to be about, which is a way to disseminate information in real time to actual friends and family, and the posting of pictures and events that are of meaning to those so posting as well as the recipients of that information. But, that isn't really what they are about, for companies such as Facebook have a market capitalization of $500 billion, this, for a company, that only went public on May 18, 2012. Facebook makes the majority of its revenue from the advertising that is done through their website, in particular, by advertisers that are specifically directing their ads to users that fit not only within their target demographics, based on their likes and other assorted pertinent information gleaned from millions of Facebook users, but also they are able to utilize the Facebook platform to sale and to target specifically to those users, and that is of immense value to them.
In point of fact, many of these social media platforms make it their policy to keep track of every click on every ad done on that platform, along with their location you are at when doing so, they track you every post, your every picture, your every friend, everything that you "liked", everything that you "tagged", and all of your personal information about your age, sex, and name, and really just about everything, forever. All of this information gathered about you, tells pretty much everything that an advertiser could ever want from a possible consumer, for when they know your age, when they have your background, when they know what you do and don't like, and so on, knowing all of that information, allows them to mold their ads to appeal to you, and specifically to people like you, because advertisers are in the business of getting business.
It would be one thing, if all your social media information that is being gathered, was really done so under your control and under your expressed and fully comprehended permission, and it is another thing when it is under the control of the social media website and therefore it is their material to do with whatever it is they so desire to do with it. Further, social media websites speak in doublespeak, so that they try to give the impression that they don't sell your individual data, and they don't do this, and they don't do that, but really, the structure of these platforms, with their third party apps, and the ease of usage and the collection of all this data, is the perfect storm, so that, when everything is collected about you, and then they say that they aren't really watching you, or that they are guarding and protecting your identity, it begs the question, as to why is all this information for years upon years, on every single click, is being stored about you, forever.