WOW. 2000 people? You know what this reminds me of? Anyone ever seen that show malcolm in the middle? Well, my little brother watches it and I was walking by, and he was getting in this car and this girl didn't want him to and the whole school was watching, so to stop him, she lied and said, "i'll never have sex with you again" and the whole school immediately started calling her a **** and saying that they had sex with her too. This is the same thing, people want to fit in and they will lie about it so they can say, "Oh yea, I saw this guy in my dreams too!" As for my dreams, if there's someone in them, they normally either don't have a face or look absolutely not like someone with a medicine ball for a head. Zephera has another good point. When you think about something, it can occur in your dreams.
I've never seen this man, but I probably will now, since he's in my memory. lol What's up with his monobrow?
This isn't some satan trying to do anything or what not, it's your unconcious mind using that image that you saw that day and using it as something else. This is as much ludicrious as when people say that dreams predict the future. Dreams are your subconcious still active and putting things you've seen or saw in your life into context.