Blogging Filter software

The Iranian dictators despise and fear any medium of free speech. Whether it be newspapers, blogs, websites or people speaking out. In the end, public opinion does matter, and a lot I might add. That's why after massive signatures are put behind petitions, they finally cave in to the demands.

If Iran uses an American blogging filtering software, Smart Filter, can't the U.S. do something to overcome the filter? Or can't the U.S. sanction worldwide companies that sell filtering software to Iran?