Last night several major Twitter accounts posted tweets showing a swastika symbol and the words “Nazi Germany” and “Nazi Holland” written in Turkish. Some accounts had their header image changed to the Turkish flag in what seems to be a mass hack by supporters of the Turkish autocrat Erdogan. Affected accounts include Forbes, Amnesty International, the European Parliament, Justin Bieber, Dortmund football club, the UK Department of Health and EyeSpy.MP. It seems the hack happened via a third-party app – possibly Twitter Counter – rather than the accounts themselves being compromised. Twitter Counter claimed in November that they had secured their accounts after a hack…