"John Flanagan VK" is a search query associated with a long-running, high-profile cybersecurity and social engineering incident on the Russian social network VKontakte (VK). It does not refer to the author of the Ranger's Apprentice book series, but to a hacker and penetration tester who gained notoriety around 2011–2016.

The core of the topic involves , including those of prominent Russian officials, oligarchs, and politicians. The data was later used to expose what many considered government hypocrisy or corruption. Who is "John Flanagan"? "John Flanagan" was a pseudonym used by an individual (or group) operating primarily from Ukraine. His real identity has been speculated but never definitively proven by authorities. He presented himself as a security researcher and activist. The Key Incident (2011-2016) Flanagan claimed to have discovered a critical SQL injection vulnerability in VK's infrastructure. Instead of reporting it discreetly (or after reportedly being ignored), he exploited it systematically to scrape the VK database.