Initially people created accounts on various social media accounts for fun or for connecting to friends and people of common interests. These unique characteristics has led to these platforms to ask for extra information about the person so as to display what is relevant to him or her. A best case scenario is Facebook that uses the data you provided to show posts that are relevant to you using its complex algorithms.
Since your social media usage can be used to determine your tastes, preferences and pet peeves, it can paint a picture to a third party of who you are as a person. It is in this light that the US Department of Homeland Security is reported to be working on a plan to monitor your social media history as part of the visa application process.
The Wall Street Journal reports that the investigators that will be engaged in this process will be looking for this kind of data following the recent unfortunate mass shooting incident in San Bernardino. The reason why Homeland Security decided to do this is because of the use of social networking sites in aiding terrorism.
This is not the only instance where your social media history can be used against you. A while ago, Facebook was spotted securing a patent where your credit score could be determined from the networks you have on social media. Another instance is how your social media history has been envisioned to be used to create a virtual form of yourself, which is not entirely crazy since we generate insane amounts of data each day.
So if you plan to visit the US soon, do not be shocked to find that they will have scoured your social media history as part of the visa application process