One might reffer to this as a natural morality. People like to be nice to others. The only variable negatively affecting this is stress. Of course, there will always be a niche market for evil, but amongst individuals this population is very small. On a group level, however, natural morality can be quite reasonably manipulated or even suspended.
History is well seasoned with incomprehensably destructive social policies.
Group think is the grotesque potential of a global brain gone bad. The computer allows for the crucial third power of info manipulation. An individual can be greatly magnified in this lense. Look at how stock market speculation is more and more influenced by on-line news and advice sites. It is probable that groupthink wrongthoughtedness or demogoguery will pose interesting challenges through the web in the near future.