The other day someone knocked on my apartment door. Now I NEVER open the door to anybody, I grew up in New York City in the 1970s, where they did all tricks in the book to get you to open the door, including one I remember very distinctly. They would blow cigarette smoke under the apartment door and yell FIRE FIRE and people would get push-in robbed that way other times the criminal would go with the superintendent (with a gun to his back) and have him knock on people's doors and they would open it, and low and behold they got push in robbed. Never happened to us, first because we were lucky, 2nd because my grandfather, a former Russian military officer never trusted a single word ANYBODY said and suspected everyone of being a spy including babies and old ladies and my Cuban Grandmother who thought the house was bugged. Those paranoia saved us many times I am sure. So back to the other day, someone knocks on my door and I wasn't expecting anybody and mind you I live in a 280 unit apartment building with 24 hour security at the front door. I said who is it, they said "oh we're the neighbors from xyz apartment and we're moving out, we have left over food and cleaning supplies and we wanted to offer them to you. I asked them again "which apartment" and they named the apartment 2 doors down from me. I said NO THANKS of course. I then called down to the security desk at the door and they said nobody was moving out that they were aware of. Later that day, I rang the doorbell of the apartment they said they were moving out of, and somebody answered the door - just opened it without even saying "who is it" and I told them what happened, they were really scared. I also asked other neighbors if the same thing happened to them and 2 said yes, but they didn't open the door either. I felt a bit relieved because it made me think they were trying random doors instead of just trying to get me for being a foreigner. People can get into any building, even ones with 5 encargados and a security guard. It's too easy to fool people and people let their guard down and get distracted. Remember OPEN YOUR DOOR TO NO ONE; EVER if you are not expecting people. With the encargado have a code word if they come to the door, one for trouble and one for safe passage. If someone is outside your door screaming they need help, or are in trouble, you of course don't want to ignore that, just call the police for them but DON'T open the door!