Fact-Check Results:

There is no credible, publicly available evidence that the "SOVEREIGN CITIZENS: A Decentralized LETS Trading Network Version 2.0" white paper (June 2025) is an officially recognized or implemented project. The NOSTR protocol and Polygon blockchain do exist, but there is no verification from reputable sources (such as official project websites, major tech news outlets, or blockchain platforms) confirming the existence or launch of this specific system as described.

The term "sovereign citizens" is primarily associated with a controversial anti-government movement, not with legitimate blockchain or economic projects. There are no open-access sources or official announcements from trusted institutions or tech platforms referencing this white paper or its claims.

To verify for yourself:

- Search for "SOVEREIGN CITIZENS LETS" on official blockchain explorers (e.g., PolygonScan) or NOSTR protocol repositories.

- Check for project listings on reputable platforms like GitHub, CoinMarketCap, or the official NOSTR website.