I agree social media creates a new kind of pressure, especially on those who are looking for approval from a peer group. We're all vulnerable at some time or another to going with the (apparent) wisdom of the crowd.
But I don't agree big data is a factor here – not in the usual industry sense of the term. It's not so much big data which is implicated here, but the cultural value attached to data of certain kinds, whether big or small. In fact, “small data” may be more influential here than big data.
Big data needs to be sourced, assembled, mined, and interpreted. Organizations are interested in big data because they hope for surprises. They want insights into trends buried in the noise. They want to be prompted to ask questions they hadn't thought of before. Big data doesn't give clear, unambiguous, and immediate signals.
On the other hand, a small piece of data such as the favorite band voted for by a group may sway someone's judgment with immediate effect. You might “like” something just because some people you admire also “like” it.
This is the power of what you could call “close data”. People might believe, or act on, some piece of information because it's issued by or valued by a particular group or channel. Big data could play a role in producing such an information nugget, but this is big data acting at one remove.
What we're seeing is, in a weird way, a return to authority. In the pre-scientific era, powerful individuals and institutions dictated what people took to be the truth. Today we're liberated by information and education to make our own evaluations. If we give up making our own judgments and just follow the opinions of others, we're giving the network a new kind of magical authority.
Groupthink is an ever-present danger. Connectivity has a tendency to magnify it. Big data isn't the culprit.