It is also likely that many of the proxies circulating on the Web in recent days are old servers that are being "pressed into service for the Iranian people," he said. "Some of the proxies in this data set are undoubtedly fresh, created by people who want to keep the Internet alive for the Iranian people."

But many are not, he said.

It's hard to say how many of the proxy services are still available to people inside the country. A majority of the services are likely to have been blocked by Iranian authorities soon after they were publicized on Twitter and elsewhere, he said. Based on anecdotal evidence and on speaking with people inside Iran, the rate at which new proxies are being created has fallen over the past few days -- and it's getting harder to get the information about them to people who need it.

The Renesys analysis comes at a time when Web traffic, video and other interactive communications in Iran as a result of a tightening censorship in the country. An analysis of the network traffic in and outside the Iranian borders by Arbor Networks last week showed that Web traffic has dropped by 50% while secure shell traffic, video and Bitorrent traffic have all dropped by over 80% because of what appears to be heavy filtering inside Iran.

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