What we really ought to do is declare free communication a human right (though I pity the person trying to figure out language allowing the suppression of dangerous misinformation, harassment, incitement to violence, etc.), then make damn sure the borders stay 'information porous'.
The U.N. has already partially done this. Unfortunately it's not a binding treaty but rather a recommendatory resolution, but through time and acceptance it's risen to the level of customary international law. It's specifically in the The Universal Declaration of Human Rights, Article 19, which states:
Everyone has the right to freedom of opinion and expression; this right includes freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers.
It is very broad and open to a large amount of interpretation, but you find that in all international laws. Removing or restricting access to dissenting political bodies access to the information would be a pretty clear cut violation of this. Once again those, this isn't an enforceable or binding treaty and several significant countries oppose it becoming one (not surprisingly, primarily China and Russia).
Separately, I disagree with government attempting to censor misinformation. I know it's a huge problem, but when the government gets involved at that level it sets a dangerous precedent of authority against people who disagree with the government or statements made by the government. Ideally I'd want to support no form of government censorship at all (leaving individual site censorship up to the operators of the site), but there are to many possibilities for direct and blatant harm to individuals through harassment, threats, posting private information, etc. for the only repercussion to be loss of access to a public site.