An analysis of Syrian internet censorship shows Wikimedia sites among the top 10 censored domains. See Table 5 on page 6.
The data they're analyzing is the filtering proxy logs from October 2011, so a lot's changed in our systems since then; for instance, the section on page 7 regarding HTTPS traffic might be completely inapplicable to us now. But I figured it was worth passing around.
Paper: http://arxiv.org/pdf/1402.3401.pdf , found via http://boingboing.net/2014/02/18/detailed-analysis-of-syrias.html . "Censorship in the Wild: Analyzing Web Filtering in Syria" by Abdelberi Chaabane, Mathieu Cunche, Terence Chen, Arik Friedman, Emiliano De Cristofaro, and Mohammed-Ali Kafaar.
Sumana Harihareswara Engineering Community Manager Wikimedia Foundation