I'm glad that some people take demonic possession seriously. . .

http://www.msnbc.msn.com/id/9339590/

But the article states:
"Interest in the devil and the occult has been boosted by films such as “The Exorcist” in 1973 and last year’s “Exorcist: The Beginning"".

I believe that the movie, "The Exorcist" serves as a reminder that demonic possession is real, but God help those who are attracted to it!
This is a good clue into how people allow this evil to come into their lives: they glorify evil and make a decision to follow and allow evil to guide them for some egoic or twisted reason.
If anything, this insight into the fact that there are people who follow and are attracted to the evil that is portrayed in "The Exorcist", could aid in answering the question why there are people in the world today who are getting possessed or are already just straight-up possessed!

JUST GO AWAY ALL OF YOU POSSESSED PEOPLE!