Twitter's announced that it can now selectively delete tweets in particular countries, allowing it to comply with individual censorship regimes while leaving offending tweets visible in the rest of the world.
Until now, when a tweet has been deleted - usually because of child pornography - it's disappeared internationally.
Announcing the move on the company blog, Twitter uses the examples of France and Germany, where pro-Nazi content is banned. But the announcement is likely to be of far more interest to certain other nations with a more restrictive attitude to freedom of speech.
"Some differ so much from our ideas that we will not be able to exist there," says Twitter.
However, this statement is, perhaps, just a little disingenuous. What the announcement will actually achieve is to make it easier for Twitter to deal with repressive regimes.
Last spring, Twitter was seen as an important aid to anti-government protesters in Egypt, Tunisia and other Arab countries. At the time, the company pledged: "We do not remove Tweets on the basis of their content."
From now on, apparently, it will.
Twitter says it hasn't yet used the new censorship facility, but that it'll let the user know when it does - as long as it's legally allowed to do so.
It says it will clearly mark when content has been withheld, by greying out the tweet or user concerned. It's also launched a new page in collaboration with Chilling Effects, similar to Google's, to publicize when content has been withheld, alongside its current DCMA notices.
"One of our core values as a company is to defend and respect each user’s voice. We try to keep content up wherever and whenever we can, and we will be transparent with users when we can't," says Twitter.
"The tweets must continue to flow," it adds. Yup, that's about right.