Don't try and lie, you play tetris, solitare or minesweep at your desk all the time. If you hear your boss coming, you hit ALT + TAB and switch over to a spread sheet or your email. I bet the fingers on your left hand can find those keys REAL quick, but ask yourself this: would you be able to toggle off the screen when confronted by a dude with a big ass gun? Chances are pretty good that when the dude with the gun is walking up to your workstation, the fact that solitare is up on your screen isn't a big deal.
Just take a look at the computer screen of the bank teller being robbed above, and a few things become evident. A) People just don't dress for bank robberies the same anymore: where is the hamburglar mask, the striped suit and the sack with the dollar sign? B) Why didn't she move that three of diamonds to the diamonds pile so she could uncover more cards. And C) This teller knew there was a camera behind her, and said "fuck it, I'm going to play solitare no matter what the bosses think.
The story of this robbery (scroll down on this site to the second bank robbery story dated 11/2/07) is as old as time. Customers always ruin our down time. Do they deserve to wait in line while we play games on our computer? No, but will we make them wait? Yes, and do you know why, cause fuck 'em that's why. We have to put up with all sorts of shit in our jobs (some people have to put up with robbery) so we deserve a little down time... on the clock.