<p>Even though this happened some years back, I think it shows how far Princeton will go (at least in the fairly recent past):
<a href=“Princeton Admits to Accessing Yale Admissions Information | News | The Harvard Crimson”>http://www.thecrimson.com/article/2002/8/2/princeton-admits-to-accessing-yale-admissions/</a></p>
<p>So do they check Facebook?
If you are close to being considered for admission, I’ll wager they google you, check Facebook, etc for any clues about your character or your future plans regardless of what any official says.</p>