This is a good article on BuzzFeed. I agree with most of it. This is an important point:
ISIS Has A Strategy To Create A Media Frenzy And News Outlets Are Struggling To Disrupt It
"Sometimes, the seeking of attention and “upping the ante” of victims is instinctive, as with young school shooters. Such mass murderers often meticulously collect clippings of media from past such incidents and obsessively follow the coverage. They "admire" and seek to emulate those who increased the numbers of victims. The Sandy Hook mass murder, carried out not by ISIS but by a disturbed young man in the US, seemed to do just that: target children, as a sick "one-upping" of sensational mass murder. In the case of ISIS, this stems not from instinct, but from a strategic understanding of the need for escalation to increase the coverage and horror.
And again and again, we are playing into their game, on their terms.
[...]
Avoid their photos, manifestos, and coverage they left behind for us except in brief mentions. Don't overreact. Report news when there is news. Don't retraumatize victims."