In Central and Eastern Europe opening government information was not only a logical step in gradual organic development of democracies. It was a radical game changer that shifted the power balance in these communities. Thanks to sharing comparable information as the ruling and economical elite citizen could suddenly become equal partners in dialogue and have gained tools to efficiently influence the public debate in favor of necessary reforms. Open government information became a threat to corrupt and nepotic networks deeply established in post communist societies. Not because they would carry direct evidence of corruption but because they documented favoritism, unfair conditions, manipulations with documents and serious flaws in the processes, law application and financial efficiency. This „evidence" was often sufficient to put a stop to a certain practice or at least demand political and legal consequences. Concrete investigations into political cases with use of newly gained right to information and government data became one of the most influential tools in reforming post-communist societies. Thanks to concrete and understandable stories it introduced societies to new paradigms, ethical and legal standards and brought evidence of destructive influence of corruption on our lives. Right to know and use government data became such an important principle that political representations do no dare to touch it. Post-communist societies paradoxically often enjoy higher legal standards and technological tools in transparency and open government than their western role models. Opening government data also liberated journalists and activists from often risky ways of using traditional sources. Our watchdog NGO -- Fair-Play Alliance has been at a forefront of these efforts and investigations. This talk will therefore explore concrete cases from our first-hand experience that have shaken political scene thanks to open information and IT tools and will explore how single cases/instances can lead to deeper reforms and less corruption. It will also analyze the vital prerequisites for efforts to hold governments accountable to avoid failures when replicating an inspiring project in different settings.