Terabyte
65 terabytes of data belonging to the Federal Air Transport Agency (Rosaviation), the Russian airspace regulator, gets lost indefinitely in a hacker attack, which is said to be one of the largest ever. The data lost includes all official documents, files on its servers, the public procurement system of Rosaviation, as well as all emails for the last one and a half years; no backups are available. As a result, the agency is forced to switch to paper-based workflow.
Sources: Aviation24.be Kommersant