In February this year, Neo and his colleagues at the “People's Army of the Fourth Awakening” contacted a local TV station to claim they had downloaded the documents from the state revenue service. They exposed salary details for senior officials through Twitter, revealing that management at a Latvian bank that received bail out money had not taken the pay cuts they promised at the time.
The revelations prompted anger in a country devastated by the global financial crisis and forced to embark on austerity measures to meet the terms of a €7.5 billion IMF and EU led bailout.
The hacker, who took his name from the central character in the Matrix film, attained cult status for his actions and was hailed as a "virtual Robin Hood".
Police have now detained the mystery tweeter, who according to local press reports, is Ilmars Polkans, a researcher in artificial intelligence at the University of Latvia's computer science department. According to AFP, hundreds of protesters chalked slogans outside the main government building in central Riga, calling for Polkans' release.
However, the suspect has confessed and criminal proceedings have been launched, although he has been freed from detention until a trial.
His unmasking came after a police raid on the house of a television journalist recently. This latter action has enraged the country's reporters and prompted the ombudsman to investigate whether freedom of speech regulations have been breached.