This topic gets a fair amount of coverage from the media and like most stories in the media these days the horror stories of kids losing out because of social media posts in more hype than reality
I will add a couple of links and quotes and then talk more specifically about my personal experience with the issue and then raise some points that might be pertinent to your question.
"Of 381 college admissions officers who answered a Kaplan telephone questionnaire this year, 31 percent said they had visited an applicant’s Facebook or other personal social media page to learn more about them — a five-percentage-point increase from last year. More crucially for those trying to get into college, 30 percent of the admissions officers said they had discovered information online that had negatively affected an applicant’s prospects." NY Times
If nearly a third of admission readers check social media, then students need to be careful about what they post. I would say that this caveat might be even more important for those seeking internships or jobs.
What The Times article leaves out, however, is the drop in the negatives as far as social media affects admission officers: [Kaplin Stats] ](http://press.kaptest.com/press-releases/kaplan-test-prep-survey-more-college-admissions-officers-checking-applicants-digital-trails-but-most-students-unconcerned)
Despite the growth in online checking, however, there’s been a dip — to 30% this year from 35% in Kaplan’s 2012 survey — in the number of admissions officers reporting that they’re finding something that negatively impacted an applicant’s admissions chances. And notably, in a separate survey of college-bound students**, more than three-quarters said they would not be concerned if an admissions officer Googled them. In response to the question, “If a college admissions officers were to do an online search of you right now, how concerned would you be with what they found negatively impacting your chances of getting in?” 50% said they would be “Not at all concerned” while 27% said “Not too concerned.” Only 14% of students said they would be “Very concerned” while the remainder said they would be “Somewhat concerned.”
While more admission people report looking at social media, more students seem to have done enough to make sure that their on-line presence will not hurt them for admission. What neither article does in any systematic way is to give a list of things that students have done that negatively impacted their chances of admission. The Times article points out a student tweeting terrible things about a school she applied to, and this would of course hurt anyone’s chances.
But what are the things that might hurt besides trashing a particular school? There are a few things I can think of that would be certain to sink a student: racist, homophobic, sexist, xenophobic comments or postings would doom anyone. But I doubt this happens much, in part because if the student did post such things there would likely already be consequences at his or her secondary school. These kinds of things would inflame at least some students at any school and it usually does not take long before someone talks about it to the school.
I also think that students have heard from the media and school officials to make sure not to put anything that would hurt them in life or in the admission process. But kids still do dumb things, and so do the rest of us too.
Let’s assume that almost all students now don’t post things that will doom them out of hand. Are there other things that might hurt them? My answer is yes, but I base this on hearsay rather than hard evidence.
Now let’s assume a student has just celebrated an 18th birthday. He or she posts a photo showing the brand new top of the line BMW that they received from mom and dad. On the face of it, this might not seem like a negative but for some in the world of admission and the world at large it would be. Most admission people are not in the 1% of the economic spread. Not by a long shot. Seeing students who jet off to Paris for the weekend, or get presents that most could never afford, and who generally come across as spoiled may well, at some level and to some extent, hurt their chances of winning over an admission officer. There are at least some in the world of admission who think rich kids have too many advantages over the rest of the population and anything that comes across as reveling in wealth might be a negative, either consciously or not.
The other example I will bring up is even more sensitive and likely to raise some comments (I hope this is the case actually). A long while ago, when paper applications were still the norm and things were far different than today, applications often came with a little space that said: photo (not required). The thought was that seeing the face, typically a yearbook picture, helped to humanize the applicant. You could see who was submitting an application. Then, however, people said that photos should not be a part of the application process as they could bias a reader. Now on the Common Application (and virtually all other applications), a photo is verboten.
Social media now undercuts the effort to take looks out of the picture (pun intended). Facebook or even Google search comes up with images pretty quickly. Let’s assume that an admission reader pulls up a Facebook page of a young woman whose profile photo shows her at a debutante ball. And it shows that there are hundreds or even thousands of photos of herself posted. This might lead some readers to think the young woman is too preoccupied with prestige, class, looks and herself. (For some it might unconsciously bias them to give her a plus as studies show that how someone looks alters how we perceive them.) Will this show up on a survey of admission readers? Probably not, but it is something worth considering.
On the other hand, it may be that a social media page might help a student. A Quoran in secondary school recently posted photos of her efforts to collect books and donate them to under-privileged students in a low-income school district. If I saw this while reading an application I would count it as a plus.
In terms of personal experience, I don’t have many to share. A while back I asked some current undergraduates to create a student group, The Mainland Student Network. Its mission was to interview students from China and also to examine the activities and things they said they did outside of the classroom. In one case a student said on renren that he/she had written a book and posted the book title there. The MSN student did some detective work and found out the book had been written by someone else.
I mention China in particular as it brings up another issue. Do some schools really want to know that much about students? The ones awash in applications certainly do, as choosing among an exceptional group of students is difficult. (It is also incredibly time consuming.) I can’t image many readers at schools that have huge applicant pools spending much effort investigating social media. There just isn’t time to get through all the materials already submitted by the applicants. Most students who send in extra stuff to supplement the application will be sad to know it rarely gets looked over at a number of schools.
Most schools in the US, however, are not all that selective. The selective schools get the most press, but the number of them is small. What many schools are looking for are reasonably good students, and reasonably good students who can pay. Many schools in the US import huge numbers of students from China. They have great transcripts, high scores, strong recommendations and essays. The problem is a lot of this is fabricated by paid "agents". They get paid a lot to write essays, and recs, alter transcripts etc. Many schools know this but often don’t put resources into checking these credentials. This leads me to believe that most schools, which need students, will not often deny a student based on a somewhat sketchy social media post or photo. If a student is reasonably good by the numbers is it worth cutting them out if they are holding what looks like an alcoholic beverage in a photo? I doubt it in most cases.
I mention the alcohol photo as it too raises issues. A person looking like they are having a great time at a party might be holding a to go cup but it would be inviting a lawsuit to turn that student down. Even if they are holding a bottle of hard liquor that does not prove they actually consumed it. Would schools want to go to court over this? I doubt this too.
I think most of what is put up about social media and schools looking things over falls into the category of providing a useful service. Telling students to take care what they post is useful. Telling anyone the same is useful too, but I don’t think it affects as many students as the surveys suggest.
The last thing I will mention is that there are now businesses that offer students a chance to submit their social media profile to them so they can go through and edit out anything that might look bad. I have no idea how any might use this but I am sure there is at least some interest in this. It means that that is yet one more way that parents and students are paying for others to help them in the admission process.