jgarzik is quite right. The SHA-256 algorithm is property of the US and export regulations for SHA-256 expressively forbid exporting the algorithm or products based on the algorithm to Iran.
I'm not sure anyone is trying to export SHA-256. Coins themselves sure as hell do not contain, nor represent any algorithm. Maybe it's illegal to allow Iranians to download the Bitcoin client (which I'm sure sourceforge is complying), but I'm not so sure using Bitcoin would itself be forbidden for Iranians.
ETA: If this is in fact the case though, we should fork Bitcoin and switch to a free algorithm before it's too late.
Besides, why the hell are we to accept getting bossed around by the USA all the time? USA is imposing all kinds of regulations internationally. Do you know that banks who haven't signed an agreement with the USA can't do business with the banks who did (i.e. all of them)? If a bank does business with an American national, or "a resident", who may even be living in a different country, without taxing them on behalf of USA and turning over the money itself, it is subject to be fined the same amount. Do you really think Bitcoin can survive within the US legal system?
Okay. Now I am supposed to view life from the perspective of the United States. If they deem something illegal, then it is. Talk about oppression.
Maybe Jeff had to react that way to protect the foundation legally. If, so, this shows that a foundation wasn't a good idea to begin with. Maybe they should clarify in writing that #bitcoin-dev belongs to the foundation, which belongs to the USA.
ETA: I'm failing to shut up about this... Now, if I talk about Bitcoin to my friends in Iran, I'm encouraging illegal activity in the eyes of #bitcoin-dev? My brain is about to explode. What a joke...