Sens. Dick Durbin, D-Ill., and Tom Coburn, R-Okla., sent a letter to Twitter CEO Dick Costolo on Wednesday demanding answers about the social media giant's new policy that allows governments to censor some tweets.

Last month, Twitter announced that it would censor tweets on a country-by-country basis in order to adhere to local laws. For example, the company can now block tweets expressing pro-Nazi sentiments in France and Germany to comply with speech regulations in those nations, although the post would still be viewable outside of those countries.

Nevertheless, Durbin and Coburn have asked Twitter to clarify how it determines whether it must comply with a government's request to censor a tweet and whether it ever considers if a request violates international human rights guidelines.

We understand that Twitter has an obligation to comply with legal requests that do not violate human rights, and we appreciate that you are taking steps to minimize the impact of censorship, the senators wrote. However, your announcement leaves important questions unanswered.

The lawmakers also encouraged Twitter to join the Global Network Initiative, a voluntary code of conduct for tech companies that require participating organizations to take reasonable measures to protect human rights. Twitter has reportedly avoided joining GNI in the past, according to the letter, which cites a 2010 letter from Twitter's general counsel stating the company thought the code is better suited to bigger companies.

The following is the full text of the letter, as posted by Forbes on Wednesday afternoon.

February 15, 2012

Dick CostoloChief Executive OfficerTwitter, Inc.795 Folsom Street, Suite 600San Francisco, CA  94107

Dear Mr. Costolo:

We write to request more information about Twitter's human-rights policies and practices.

We commend you for providing an important tool to democracy and human-rights activists. Twitter has helped activists in the Middle East and elsewhere to organize demonstrations and publicize human-rights abuses. At the same time, Twitter and other social networking technology have created what Internet expert Evgeny Morozov calls a digital panopticon that repressive regimes use to crack down on activists. As Scott Shane wrote in The New York Times, A dissident's social networking and Twitter feed is a handy guide to his political views, his career, his personal habits and his network of like-thinking allies, friends, and family.

Freedom of Expression

Our inquiry is prompted by Twitter's recent announcement that it would begin censoring content in particular countries. Tweets still must flow, a Twitter blog post on January 26, 2012, said, 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 (http://blog.twitter.com/2012/01/tweets-still-must-flow.html). The Twitter Help Center page on Country Withheld Content further explains, if we receive a valid and properly scoped request from an authorized entity, it may be necessary to reactively withhold access to certain content in a particular country from time to time (https://support.twitter.com/articles/20169222).

We understand that Twitter has an obligation to comply with legal requests that do not violate human rights, and we appreciate that you are taking steps to minimize the impact of censorship, by, for example, making censored content available outside the country where it is withheld, only censoring content in response to a government request, and providing notice when a tweet is censored.  However, your announcement leaves important questions unanswered.  Please respond to the following questions:

1.      What procedures does Twitter follow when you receive a request from a foreign government to withhold content?  Are these procedures in writing?  Have Twitter's employees been trained in these procedures?

2.      Do you maintain a written record of all such requests?

3.      How do you determine whether such a request is valid and properly scoped?

4.      Do you require that such a request follow the legal process required by the foreign government's laws?

5.      Do you make an independent assessment of whether such a request complies with the foreign government's laws?

6.      Do you assess whether such a request complies with international human rights laws?

7.      If you determine that such a request violates the foreign government's and/or human rights laws, how do you proceed?

8.      In what circumstances would you decline or challenge in court such a request?

9.      Which Twitter official is ultimately responsible for authorizing the withholding of content?

We are also concerned about whether Twitter has in place adequate safeguards to protect the privacy of its users. We commend Twitter for allowing the use of pseudonyms, which is an important protection for democracy and human-rights activists in countries with repressive governments. We understand that Twitter must cooperate with legitimate law enforcement efforts, and we appreciate that Twitter attempts to notify a user before turning over his or her private information. A Twitter blog post on January 28, 2011, The Tweets Must Flow, states, While we may need to release information as required by law, we try to notify Twitter users before handing over their information whenever we can so they have a fair chance to fight the request if they so choose (http://blog.twitter.com/2011/01/tweets-must-flow.html).  Again, important questions remain unanswered.  Please respond to the following questions:

1.      What procedures does Twitter follow when you receive a request from a foreign government for the private information of a Twitter user?  Are these procedures in writing?  Have Twitter's employees been trained in these procedures?

2.      Do you maintain a written record of all such requests?

3.      Do you make an assessment of whether complying with such a request may put the human rights of the Twitter user at risk?

4.      Do you require that such a request follow the legal process required by the foreign government's laws?

5.      Do you make an independent assessment of whether such a request complies with the foreign government's laws?

6.      Do you assess whether such a request complies with international human rights laws?

7.      If you determine that such a request violates the foreign government's and/or human rights laws, how do you proceed?

8.      In what circumstances would you decline or challenge in court such a request?

9.      Which Twitter official is ultimately responsible for authorizing the disclosure of private user information?

10.  In what circumstances do you notify a Twitter user that you have handed over his or her information?

11.  Where do you store the private information of your users?

Global Network Initiative

As you know, we have urged Twitter to join the Global Network Initiative (GNI), a voluntary code of conduct for internet and communications technology companies that requires participating companies to take reasonable measures to protect human rights.  We believe that the GNI has potential to advance human rights if member companies fully implement the GNI's principles and the GNI's membership is expanded.

In a February 19, 2010 letter, Twitter's General Counsel told us, [W]e have not had the luxury of time to be able to fully evaluate GNI.  It is our initial sense that [GNI] is better suited to bigger companies.  As the GNI testified at a March 2, 2010 hearing on internet freedom that we held, GNI membership dues and requirements differ based on a company's size and resources:  While membership requires executive-level commitment to the principles and GNI framework, implementation of GNI commitments will vary for each company, depending on differences in size, markets, business models, products and services.

We appreciate that joining GNI would require a significant investment of time and resources, but Twitter now has hundreds of employees, over one million active users, and is used by people in nearly every country in the world (http://blog.twitter.com/2011/08/your-world-more-connected.html, http://twitter.com/about, http://blog.twitter.com/2011/09/one-hundred-million-voices.html).  Twitter clearly faces the significant human-rights issues that the GNI is designed to help companies address, namely government pressure to violate the freedom of expression and user privacy.

1.      Now that you have had two additional years to evaluate the GNI, will you consider joining?

2.      GNI members undergo an independent assessment and evaluation of their human-rights policies and practices.  Does Twitter undergo such an external audit?  If not, will you?

3.      GNI members employ human rights impact assessments to identify circumstances when freedom of expression and privacy may be at risk when entering new markets; considering potential partners, investments, and suppliers; and introducing new products and services.  Does Twitter conduct such human rights assessments?  If not, will you?

4.      GNI members provide training on human rights, freedom of expression, and user privacy to its employees.  Does Twitter provide such training?  If not, will you?

5.      Please provide a copy of any human rights guidelines and policies that Twitter has in place.

Thank you for your time and consideration.  We look forward to your response at your earliest convenience.

Sincerely,

Richard J. Durbin

Tom Coburn, M.D.