Europe can shut down terror attacks quickly. But it's still unable to prevent them

London (CNN)As the horrors of Vienna unfurled, the timing and abhorrent methodology was familiar -- indiscriminate lethal violence against the undefended, the night before Austria's lockdown set in, and on the eve of the US presidential elections. Yet, after six years of ISIS-inspired mindless murder, last week's attack, in which four people were killed, perhaps stood out less in its brutality, but instead in the woefully irresponsible noise and video on social media that came with it. CCTV footage of an innocent man being shot on two occasions, posted unedited, with complete disregard for the victim's family. Similar video of a policeman being shot. Incorrect reports of multiple attackers,...