Some outstanding questions regarding Twitter’s new country-specific censorship system:

1. Mobile clients: Will Twitter’s mobile clients also get the ability to let the user manually choose their jurisdiction, just like they now can on the full browser client? Currently neither the mobile web client nor the phone apps let you. This matters because much (most?) tweeting is done from mobile devices, especially when people are busy bringing down dictators.
2. Transparency: Twitter says it will promptly notify users if their content has been withheld, “unless we are legally prohibited from doing so.” It also says it will post requests to withhold content to the Chilling Effects website. Does that include all requests, or only those it is not prohibited from posting? Does Twitter anticipate operating in countries where it is illegal to make public the specifics of a takedown request in any jurisdiction?
3. Country-withheld content: Here is my best guess at how the country-specific censorship system works, based on testing: Before the browser requests new tweets from Twitter’s server, it first checks a cookie to see if the country location setting has been manually overridden. If it has not, then Twitter geolocates the IP address of the browser and filters the resulting twitter feed for that jurisdiction before sending the tweets along to the client. If the country setting has been manually overridden, then the browser sends along the chosen country to the server, which proceeds to filter the feed for that country, rather than the geolocation IP address. Is this correct?
4. Forms of censorship: Twitter states that sovereign jurisdictions can request the withholding of individual tweets and/or of entire accounts, and also writes that this withholding can only be reactive, in response to “a valid and applicable legal request.” The problem is, I can think of several scenarios where this might not be enough to avoid breaking local laws. For example:

• France and Germany among others prohibit search engines within their jurisdiction from linking to specific sites they deem illegal. If Twitter is not going to use a block list to pre-emptively withhold tweets containing such links in these countries, will it be breaking the law?
• If a tweet has been retweeted (natively, or by using RT, or by using quotes, or after a slight edit) by a number of users by the time a withholding request arrives which Twitter agrees to comply with, will there be an effort to remove these retweets in that jurisdiction? Might not the legal entity making the request reasonably expect these to all be one-and-the-same tweet?