He was sentenced to 100 hours of community service, Poikans' attorney Ilmars Punka told LETA Monday.
In 2010, Poikans made international headlines under the pseudonym of 'Neo' when he leaked tax records of the Latvian elite.
The Riga Central District Court acquitted Poikans last June, but the verdict was appealed to the Riga Regional Court by the prosecutor and representatives from "ABLV banka". The Revenue Service did not appeal the district court's ruling.
The charges against Poikans were brought by the Finance and Economic Investigation Prosecutor's Office, which said that in 2009 Poikans, using a hole in the Revenue Service's EDS system, obtained commercial information from the system. According to the charges, Poikans obtained commercial information from the EDS - 250 electronic documents overall.
The prosecutor claimed that Poikans, in downloading and later making public the EDS data that contained a large amount of information about companies and residents' personal data, infringed on these persons' right to privacy.
The full version of the ruling will be released on November 17.
In 2010 Poikans obtained 7.5 million classified files from Latvia's tax authority, the State Revenue Service (SRS) after discovering a simple flaw in its electronic security system.
He released selected data into the public domain via investigative journalist Ilze Nagla to show that senior state employees were continuing to pocket large wages and bonuses while hundreds of lower-paid workers were losing their jobs and having wages slashed by a third as part of an austerity drive.
His disclosures included senior staff at bailed-out Parex Bank, the financial regulator, the Latvian central bank and state-owned power utility Latvenergo.
Months later, Neo's identity was revealed to be Ilmars Poikans, a researcher and computing expert at the University of Latvia. He was subsequently named Latvia's "European of the Year" in an online public vote.