Islamic State Beheading Video

We hear reaction to the video posted online that appears to show the beheading of the American journalist James Foley who went missing in Syria in 2012. The jihadist militant group who call themselves Islamic State said the killing was revenge for US air strikes against its fighters in Iraq. How do you think the world should react to the killing? Also, after the video was shared online the hashtag #isismediablackout has been trending on twitter. Twitter has since said it will block any accounts sharing footage of the video. Should there be a media blackout? And if so, why is this case exceptional? Isn't it better to see exactly what IS is doing?