President Obama recently gave some advice that many job-seekers could use: Be careful how you act online.

While the president was speaking to high school students in Arlington, VA, a 9th-grader asked him for some tips on how to become the Commander in Chief.

“First of all,” Obama answered, “I want everybody here to be careful about what you post on Facebook,” because “it will be pulled up again later somewhere in your life.”

A lot of job candidates probably wish they’d heard and followed that advice. According to a recent CareerBuilder survey, 35% of managers say they’ve turned down someone for a job because of what they found on social networking Web sites.

Tags: Facebook, Obama, social networking