What Cisco answers
I asked Cisco what they have to say about selling products that the Chinese government uses to block their people when they want to browse sites considered unbeneficial to Chinese political stability.
Here is what they answered:
Cisco has not specifically designed any products for the Chinese government, or for any regional market to block or filter content. The products Cisco sells in China are the same products it sells worldwide. Furthermore, Cisco does not supply any encryption source code or encryption design technology to the Chinese Government or any other government that would allow them to redesign or modify functionality of our products.
This means that this kind of product is usable for any purpose and that Cisco is not responsible for bad use of it.
It is right. It means that, as it happens with weapons, technology is a kind of product that could be embargoed. If we really think that freedom of expression is important, we could think about it.
Or we could think the other way around: let's sell so many things to the Chinese that their system will collapse. As George Soros won soviet Hungary by giving them so many copiers that free press emerged. Which is the right one?