Twitter has refined its ability to block posts from appearing (read: censor) in user streams on a country by country basis.
As explained on the Twitter blog:
As we continue to grow internationally, we will enter countries that have different ideas about the contours of freedom of expression. Some differ so much from our ideas that we will not be able to exist there. Others are similar but, for historical or cultural reasons, restrict certain types of content, such as France or Germany, which ban pro-Nazi content.
Until now, the only way we could take account of those countries’ limits was to remove content globally. Starting today, we give ourselves the ability to reactively withhold content from users in a specific country — while keeping it available in the rest of the world. We have also built in a way to communicate transparently to users when content is withheld, and why.
We haven’t yet used this ability, but if and when we are required to withhold a Tweet in a specific country, we will attempt to let the user know, and we will clearly mark when the content has been withheld. As part of that transparency, we’ve expanded our partnership with Chilling Effects to share this new page, http://chillingeffects.org/twitter, which makes it easier to find notices related to Twitter.
"In the face of a valid and applicable legal order," a Twitter spokeswoman tells TechPresident’s Nick Judd, “the choice facing services is between global removal of content with no notice to the user, or a transparent, targeted approach where the content is removed only in the country in question.”