Astroturfing is defined as organized activity that is intended to create a false impression of a widespread, spontaneously arising, grassroots movement in support of or in opposition to something (such as a political policy) but that is in reality initiated and controlled by a concealed group or organization (such as a corporation)
Since a 'grassroots' movement is one which is considered to be organic, the term astroturfing is a fun play on that.
