How do you know whether cologne is counterfeit if i bought it in NYC?

Question

I always see these people selling colognes in the street for half price (Polo Black for $20, etc.). I bought it, and it smells real, but I can't tell for sure. The box and container were sealed and look real.

What's the deal?

Answer 1

Is it counterfeit? Likely.
Is it real? Maybe.
If it is real, is it stolen? Most definately, odds reaching certainty.