Examples:1. 19 Year Old Kid builds a startup squatting at AOL.
2. Young Steven Spielberg squatting at Universal Studios for 2 months.
The story of Steven Spielberg claiming that he squatted for 2months/years is rebutted in the media. It is a possibility. :) (http://www.anecdotage.com/index.php?aid=14372)
Another example of studio squatting http://en.wikipedia.org/wiki/Daedalus_Howell#Controversy
So, give some love to access control systems. :)