Servers/Dec 2015 DDOS issue
On the morning of 8th Dec 2015 OpenStreetMap.org suffered from a partial outage due to a major denial of service attack against the UK Academic Network.
The issue was a very widespread outage affecting DNS and network connectivity for the whole UK academic network, JANET. An outage like this is extremely rare. Read more in this IT industry news coverage. All OpenStreetMap servers remained operational and seemed to serve traffic internally in the UK without interruption. The outage mostly affected users outside of the UK.
The operations team monitored the situation and found the connectivity was being restored gradually, with worldwide traffic returning to our servers https://twitter.com/OSM_Tech/status/674225631966662657