Twitter later posted a blog update answering questions raised in the censorship row:

Q: Do you filter out certain Tweets before they appear on Twitter?

A: No. Our users now send a billion Tweets every four days—filtering is neither desirable nor realistic. With this new feature, we are going to be reactive only: that is, we will withhold specific content only when required to do so in response to what we believe to be a valid and applicable legal request.

As we do today, we will evaluate each request before taking any action. Any content we do withhold in response to such a request is clearly identified to users in that country as being withheld. And we are now able to make that content available to users in the rest of the world.

Q: What will people see if content is withheld?
A: If people are located in a country where a Tweet or account has been withheld and they try to view it, they will see a alert box that says “Tweet withheld” or “@Username withheld” in place of the affected Tweet or account.

Q: Why did you take this approach, and why now?
A: There’s no magic to the timing of this feature. We’ve been working to reduce the scope of withholding, while increasing transparency, for a while. We have users all over the world and wanted to find a way to deal with requests in the least restrictive way.