The east-German city of Halle was still reeling from the anti-Semitic motivated attack on Thursday October 10th, while tech giants tried to explain how the attacker’s live video found its way across the web, despite safeguards to prevent this.
In Halle, a man attempted to enter a synagogue with weaponry and explosives, but ultimately failed. He then shot another man and a woman and injured other people before he got shot by police. While he tried to flee while injured, first in his car, then in a taxi, ending in an accident and his arrest after about half an hour.
The perpetrator of the Halle attack recorded everything and was streaming live online the whole time. According to the streaming platform Twitch, on which the video was shared, only five people were following the approximately 35-minute live broadcast on its site at the time. But 2,200 people subsequently saw the recorded video still on the same platform before it could be locked.
The German news magazine, Der Spiegel, has tried to analyse how the video could spread across the internet, despite the fact that big companies, such as Facebook, Microsoft, Twitter and YouTube, have protocols in place to counteract abuse of their digital platforms.
The Global Internet Forum to Counter Terrorism (GIFCT) was established in 2017 by those four founder companies to make a dedicated effort to disrupt abuse of their webspace by terrorists or violent extremists, it says on the Forum’s homepage.
In this case, however, Der Spiegel pointed out that the so-called process of ‘hashing’ the video fell short. A digital fingerprint of a video is created and gets shared in a common database for the partnered companies to use.
Usually, sharing a link or content would no longer lead anywhere, once the source has been hashed by Twitch and then blocked by everyone with access to the database. But once the content gets changed ever so slightly, it can no longer be recognised using this approach.
A tactic which became more widely prominent after the New Zealand Christchurch mosque shooting in March. Facebook for example has tried to start using additional sound recognition software as a result.
As an explanation on why their image and video matching technology, which Facebook called “effective at preventing the spread of propaganda from terrorist organizations,” did not catch copies of the video from the attack in New Zealand, the company replied, “what challenged our approach was the proliferation of many different variants of the video, driven by the broad and diverse ways in which people shared it,” and vowed to learn how better to understand the techniques used in these instances.
Twitch stated its analysis so far suggested that people had been coordinating to share the video in an organised way via other online services as well. The company said it will block every account that gets detected trying to share the video from Halle in any shape or form.