Killing journalists on the basis of shared religion and skin colour is really not cricket. It would also be counterproductive as it would generate many willing martyrs and shatter the little remaining goodwill that the international community has towards the US. I doubt the last shreds of UK public support for coalition operations would survive such an action, for example.
And, to quote a certain war hero and one of the few Americans with any scruples, it's not about them it's about us.
However, both wideband jamming and spoof broadcasts could be used if a real need existed other than a despotic desire to censor unfriendly news.