First off, a short bio: I'm 20, male and live in NYC. Living in NYC, you learn to be on your guard every time you happen down a dark street. You do that or you learn your lesson soon enough.
This story happened a few weeks ago. Not sure of a specific date. Right before the Christmas holiday. Anyway, I live in New York City with my wife and two other roommates. There are four of us all together. I usually stay out later that everyone else because I have late classes and meetings, things like that.
One evening, I was walking to my apartment building, which is located in The Village. I entered the building and noticed a guy was walking in the door behind me. I didn't pay any attention to him, because the streets were busy that night. It could have been anyone that lived there. I live on the sixth floor, so there's no possible way I can know everyone that lives on every floor in every room.
I had an uneasy feeling as soon as I saw the guy. He was about 6'1", broad-shouldered, and he was wearing casual clothing. I had made the mistake of carrying my laptop with me that night, so anyone who saw it instantly thought I was wealthy or something (I'm not in the slightest).
I decided to take the stairs and the guy followed me. I pretended like I was on my cell phone and got off on the fourth floor. (I have a friend on the fourth floor and I didn't want the guy knowing where I lived.) He continued to follow me and I went to my friend's door and pretended like I had lost my key. I turned around and the guy was watching me. I politely asked him if he needed anything, and he walked away, back into the stairwell.
After that, my friend opened the door and he let me inside. I stayed there for a few minutes and told him about the guy that had followed me, etc. (Not to mention, my friend was slightly irritated that I had led the man here.) But, eventually I left and went back to my floor. I walked into my apartment, threw my laptop case down, and locked the door, just as someone knocked. I asked who it was, and I was answered by another knock. We have one of the doors that has the chain-style lock, and a deadbolt. I slid the chain into place and looked out, and it was the same guy that was on the fourth floor. He attempted to force the door open, but I managed to get it shut. And I called the cops immediately.
Unfortunately, that guy was never caught. But, living in NYC, that's only ONE of several occurrences that has taken place. Just a fair warning: Be careful and trust your gut feeling!