Hundreds of thousands are marching in Bangladesh's capital Dhaka to demand the government start policing the blogosphere. The marchers want a blasphemy law - requiring the death penalty for people who insult Islam online. At least four bloggers were arrested this week for criticising the country's religious parties. The government accused them of inciting violence, but critics say it's stifling free speech. An Al Jazeera correspondent reports from Dhaka.
