I completely agree with the fact that anything we post in the cyber space do give away facts about ourselves and in general looking at someone's social media (and especially blogs) one can end up knowing the person more than the one living next door... but said that, many people do manage to leave the wrong impression by picturing things differently from how they are in reality. Many fake stuff in order to look better and show their life being nicer... I wrote about it and did a livestream a while ago too - here https://steemit.com/life/@anialexander/social-media-how-real-we-are-there