Its not uncommon for keys to be lent to researchers who pull all nighters, saves finding and bothering security every time you want a fag/fresh air, and if you have blagged a key, why would you use the main enterence which usually adds .5 miles of additional walking to get to where you need to be, of course by doing so you bypass any of the people counting mechanisms the place may have, so wont be missed and "shouldnt" be there....
Biting the hand that feeds IT
