http://www.cracked.com/article_19161..._ibsrc=fanpage

A large part of this internal mess comes from the endogenous retrovirus. A normal virus works by moving into a host cell and using it to reproduce, but retroviruses reproduce by actually mixing their own genetic material with the DNA of the host cell they're invading. If a normal virus is a home invasion robber, busting down your door and smashing up your stuff, a retrovirus is the creature from Alien, impregnating you with its horrible seed and producing a twisted mockery of everything you once were, and then laughing as that atrocity murders all of your friends. Metaphorically speaking, of course.


Oh this article is good. I realized that this possibly explains some of the people that look a little, off.
I also realized that some persons of less than benevolent intentions could manipulate the human genome by simply creating and releasing these viruses undetected into the population to engineer any number of sinister outcomes.
By this same token, some person of a more caring but, secretive nature could use this same idea to improve the evolutionary direction of the human species. If I were such a person, this would be the instrument I would use.

Real Science Fiction stuff that has every possibility of reality and is not beyond our current technology to implement. Imagine a scenario where we have good hackers vs the bad hackers on the net and apply it to a battle of retrovirus engineers.