DDoS attacks were among the top cyber threats in 2016. A DDoS attack means that one component in a data network (e.g. the server) becomes overloaded and therefore blocks the whole system. This is what denial of service means. If a larger number of systems cause the overload, it can frequently indicate that an attack is ongoing, which is called a distributed denial of service (DDoS). But the record DDoS attack on the DNS provider Dyn allowed conclusions to be drawn. It appears that the attackers linked devices belonging to the Internet of Things to produce a botnet . This huge network of "slave" devices such as IP cameras, baby monitors, refrigerators and coffee machines – all of them hooked up to the Internet and each with their own significant security vulnerabilities – allowed the hackers to seize almost unimaginable resources. This was enough to take down Dyn , and with it even prestigious companies like Amazon, Airbnb or PayPal. Supposedly, the hacktivist groups Anonymous and New World Hackers used the attack as revenge for the Internet exile of WikiLeaks founder Julian Assange. Soon afterwards, the following message was posted on the WikiLeaks Twitter account: "Mr. Assange is still alive and WikiLeaks is still publishing. We ask supporters to stop taking down the US internet. You proved your point."