FINDING · EVALUATION

The single Chinese PlanetLab node reported 176 censored domains — more than all other 173 agents combined. Turkey (6 domains), Jordan (5), and Hungary (1) were the only other countries with any detected filtering. 86% of agent nodes across 33 countries reported zero filtering events.

From 2011-sfakianakis-censmon — CensMon: A Web Censorship Monitor · §4.2, Table 2 · 2011 · Free and Open Communications on the Internet

Implications

Measurement infrastructure yields diminishing returns from broad global coverage; the marginal value of additional vantage points is concentrated inside China and a handful of secondary censoring countries.
Country-specific blocking profiles are so divergent that per-censor configuration tuning is warranted rather than a single global circumvention policy.