As senior year approaches, Becca is ready to start the college admissions process. She is already familiar with the traditional application profile: standardized test scores, grade-point averages, extracurricular activities and a combination of other factors. But beyond those long-standing worries, Becca has a new digital dilemma to worry about—her Facebook profile.

“I am a little concerned,” said Becca, a high school senior in North Carolina. “It’s scary to think college admissions officers look at everything you post online.”

Becca is one of millions of rising seniors who need to be aware of college admissions officials using Facebook and other social media sites to learn more about their applicants. With this new addition to an already stressful process, some students are now assuming the worst and implementing online protections to hide their digital trail.

It seems these students have good reason to worry. In a recent Kaplan Test Prep survey of the top 500 universities in the nation, 26 percent of admissions officers say they used Facebook and 27 percent used Google to help evaluate a student.

“We work with tens of thousands of students ever year, and we get all kinds of questions about the role of social media in the admission process,” said Russell Shaffer, senior communications manager at Kaplan Test Prep. “We wanted the guidance we’re giving our students to be informed with information provided by decision makers themselves.”

Schaffer said these statistics should make students more aware of their online presence. The biggest takeaway, he said, is that the percentage of admissions officers who discovered something online that negatively impacted the student’s chances tripled from 12 percent in 2011 to 35 percent in 2012.

“The big change in admissions officers was finding negative material. These things ranged from underage drinking, essay plagiarism and generally illegal activities,” Schaffer said. “Admissions officers recognize that the traditional application is the polished version of the applicant. What they find online is the raw version.”

Most colleges use Facebook or social media sites to first get to know the applicant. But Schaffer warns that information students post online is always fair game.

Some students go as far as changing their names on Facebook or even deactivating their accounts as admission season rolls around. In an article from Time magazine, New York high school students show this growing trend of hiding online activity in this cat-and-mouse game.

Still, many large universities do not have the time to conduct thorough online research. Jeannine C. Lalonde senior assistant dean of admission at the University of Virginia, a school of roughly 21,000 students, said there just isn’t enough time and manpower. Virginia does not look up every applicant online, but if admissions officers come up with suspicious information that prompts a quick Google search or an inappropriate tweet, it may hurt the applicant’s chances of getting in.

Michael P. Gulotta, associate director of admissions at American University, recalls similar experiences. On one occasion when he was working for a different university, he remembers conducting roughly 300 student interviews one weekend.

“We would search on Twitter to see if any students had tweeted about their experiences,” Gulotta said in an e-mail. But when one student tweeted inappropriate things about other students in attendance, “the comments cast a cloud over his application, and ultimately, the student was not offered admission to the university.”

Still, Schaffer, the Kaplan communications manager, tells students not to be too alarmed. “Although a quarter [of admissions officers] said they use these tools, it’s still not something they do on a regular basis,” Russell said. “It’s still the traditional factors that have the biggest impact.”

And while admissions officers sometimes search for red flags, they also look out for positive signs. Schaffer said that whether it is dancing, singing, drawing, or playing sports, social media–when used appropriately–can be a great way to stand out.

So as Becca and millions of students just like her apply for college, most admission officers advise the same thing: be aware of what you post online and keep your digital trail clean.