At an public place with lots of ATMs available; many people around; seemed to be near Harvard Square judging by the age and look of the crowd.

Three guys took my ATM card and my keys, although they didn't seem interested in my keys... they wanted to throw my keys underneath the ATM so it would take me a couple of minutes to get them back... However, every time they'd drop or throw them, someone would pick up the keys and give them back to the thieves. Finally the guy holding my card tossed the key to the third thief, who slid them along the ground so they ended up against the wall under an ATM. I went to pick up the keys and saw the first guy looking at my balance. He printed it out and handed it to the second thief, and you could see how pleased and surprised they were at how much was in there.

I was trying to think of what to do, trying to remember what my withdrawal limit is, trying to remember whether my cell phone was in my pocket...

I was not frightened, only inconvenienced.