Even though they are little more than rednecks with AKs, we see articles on them all the time
Because where they are located as a group (not to be confused with the "lone wolf" types that the communication in question is trying to egg on), they've brutally killed thousands of people, and are armed with pretty nice toys, left behind by the courageous Iraqi regulars who went running for the hills when ISIS showed up.
Imagine if the same amount of press was done with some far right-wing militia group in the US.
If some group in the US did anything LIKE what ISIS is doing in across huge swaths of land in the Middle East, and did so with tens of thousands of people gleefully participating, then you'd see far MORE press about it that we're seeing about ISIS. But because there are no such huge groups of prisoner-burning, foreigner-decapitating militarized crazies occupying the equivalent of large portions of multiple states in the US, there's nothing to talk about.
ISIS's propaganda is working so well that even Europe has all but recognized them as a sovereign state.
Well, they control land, have a standing army, control and sell oil resources, and have people from around the world traveling to submit to their regime. That's about as (or more) put together as, say, Yemen is right now - a country that the EU recognizes.
If ISIS loses the ability to show some atrocity or chop off another head
So you're proposing control over the internet as a solution, here?