The Islamist marchers listed 84 bloggers who they demand be arrested or hanged, In February an atheist blogger named Rajib was stabbed to death a month after blogger Asif Mohiuddin was nearly killed for his beliefs.
MORE: http://www.vice.com/read/bangladeshs-islamists-call-for-death-of-atheist-bloggers
See also...
On April 25, We Stand with Bangladeshi Bloggers and Activists
http://www.americanhumanist.org/news/details/2013-04-on-april-25-2013-we-stand-with-bangladeshi-bloggers
Worldwide Protests for Free Expression in Bangladesh
http://www.centerforinquiry.net/cfe/page/protest
Earlier...
Bangladesh Islamists rally for blasphemy law
http://www.cnn.com/2013/04/06/world/asia/bangladesh-blasphemy-protest/index.html