Brian Hindley and Hosuk Lee-Makiyama have published a working paper on "Protectionism Online: Internet Censorship and International Trade Law." From the abstract:
This paper suggests that many WTO member states are legally obliged to permit an unrestricted supply of cross- border Internet services. And as the option to selectively censor rather than entirely block services is available to at least some of the most developed censorship regimes (most notably China), there is a good chance that a panel might rule that permanent blocks on search engines, photo-sharing applications and other services are inconsistent with the GATS provisions, even given morals and security exceptions. Less resourceful countries, without means of filtering more selectively, and with a censorship based on moral and religious grounds, might be able to defend such bans in the WTO. But the exceptions do not offer a blanket cover for the arbitrary and disproportionate censorship that still occurs despite the availability to the censoring government of selective filtering.
And from the paper:
... although the dispute settlement mechanism of neither the WTO nor other trade instruments could be used to eliminate Internet censorship, they might limit the use of its more commercially damaging forms. For businesses, trade with countries ruled by authoritarian regimes, or with countries where the concept of the rule of law is still under development, will always be difficult – if not outright dangerous. Contesting arbitrary and disproportionate blocks on access to such markets will incrementally help to reduce legal uncertainty and therefore contribute in the long run to a regulatory environment where the risks and costs of market participation are foreseeable.
