This is very interesting subject for me as sociologist, I think pretty much everyone should be away of how it works.
Overton Window - the theory that describes as a narrow "window" the range of ideas the public will accept. Saying in easy words - very tricky way how group of radical/extreme movement can make their beliefs not only acceptable (even if that was Taboo in all public before), but also make it legal.
Sometimes I am really shocked to read global and UK news, but this theory perfectly describes how it works, amazing science!

For Russian speaking I advice to read this article
http://rvs.livejournal.com/27431.html

In English Wiki and many more links:
http://en.wikipedia.org/wiki/Overton_window

What is the most ridiculous thing that was legalized in your country based on this theory?
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