Want to know what gets Iranian Web censors' transgenic goat?
Well, it's tough to tell.
Even the presidential campaign sites of Republican hawks Michelle Bachmann and Mitt Romney, who recently called Iran's theocratic regime "unalloyed evil" slip through, as do the main sites for the State and Defense Departments and the CIA.
The New York Times and Washington Post sites both get through, but the left-leaning Daily Kos site is blocked, as is rightwing blogger Michelle Malkin's.
The main website of the American Israel Public Affairs Committee isn't censored, according to the site, but the English gateway to Israel's parliament, the Knesset, is.
Sites like Blocked in Iran have been around for several years with varying degrees of reliability, said Robert Guerra, director of the Freedom House think tank's Project on Internet Freedom. Those sites typically rely on a proxy server inside the country, Guerra said, so the search results may reflect the foibles of that particular server rather than government censorship and sophisticated technology could tag the server itself for a heightened level of censorship, skewing the results.
Guerra's not familiar with the Blocked in Iran site itself, he said, and doesn't know of a surefire test for determining which sites are blocked in the Islamic republic and which aren't. A simple test for sites blocked in China, the nation with the most complex and long established online censorship regime, is to simply search for sites on Baidu.com, China's most popular search engine, he said.
"Those comparison sites have been around for a while and they're cute and they're good, but they're basically about Internet censorship 1.0," Guerra added.
What's often called second generation Internet censorship or censorship 2.0, includes distributed denial of service attacks on critical sites, malicious patches that change content on the sites and armies of paid commenters who drown out each critical comment or blog post with a thousand opposing voices.
"You're not going to pick up that kind of nuanced repression of criticism by just comparing websites," Guerra said.