Why is it that so many atheists attack Christianity and other western religions, but not eastern ones?

Every time that I watch a TV show or hear people talking about religion on a forums or a blog, it is usually Christians or other western religions that are being attacked, not eastern ones like Buddhism or Hinduism. Is the western world becoming less "western" and more engulfed with eastern thought? Or are people just too obsessed, as they carry anti-Christian/anti-western bigotry?