Admission officials do not routinely do Google searches to seek out information about their applicants. But it DOES happen … most often when the application says something atypical that the college folks want to learn more about. Sometimes this occurs when the applicant mentions a major achievement that’s likely to have made its way to Cyberspace, or it may be when there are inconsistencies in the application and its supporting materials (e.g., if the student claims to have won a national science award and yet the science grades and test scores are low). Sometimes an inconsistency is legitimate (e.g., a future Enrico Fermi neglects his studies in favor of independent research) but this would probably spur the admissions readers to look for corroboration of the award. They often begin the follow-up with a call to the school counselor, but they might take a trip to the Internet as well. So if your application discusses a start-up company that you founded, a curious admission staffer might indeed turn to Google to find out more … or not.
If you want admission committees to know about your out-of-school achievements for sure, you must tell them in your applications. If the explanation doesn’t fit well in your essays, the “Additional Information” section of your applications would be a good place to put it. However, when candidates DON’T want admission officials to know more about them than what they reveal in their applications, then the outcome is in the hands of fate. Many admission officers are way too busy to be investigative reporters while others seem to enjoy the challenge.