PEN America published a report this week summarizing the findings from a recent survey of 772 writers around the world on questions of surveillance and self-censorship. The report, entitled "Global Chilling: The Impact of Mass Surveillance on International Writers," builds upon a late 2013 survey of more than 500 US-based writers conducted by the organization.

The latest survey found that writers living in liberal democratic countries "have begun to engage in self-censorship at levels approaching those seen in non-democratic countries, indicating that mass surveillance has badly shaken writers' faith that democratic governments will respect their rights to privacy and freedom of expression, and that—because of pervasive surveillance—writers are concerned that expressing certain views even privately or researching certain topics may lead to negative consequences."

Specifically, more than 1 in 3 writers living in "free" countries (as classified by watchdog Freedom House) stated that they had avoided speaking or writing on a particular topic since the Snowden revelations, and only seventeen percent of writers in these countries felt that the United States offers more protection for free speech than their countries. A whopping sixty percent of writers in Western Europe and fifty-seven percent in the remaining Five Eyes countries (Australia, Canada, New Zealand, and the UK) think that US credibility “has been significantly damaged for the long term” by NSA spying.

PEN also asked respondents to share their feelings about surveillance in their own countries, and found that in every grouping ("Free", "partly free," and "not free" by Freedom House standards), more than seventy-five percent of writers are "very" or "somewhat" worried about government surveillance at home.

As PEN so aptly states in their report, "the harm caused by surveillance to free expression, freedom of thought, and creative freedom is unmistakable." And as the findings demonstrate, surveillance is not solely an issue of privacy, but also one of free speech, freedom of association, and innovation.

In their conclusion, PEN calls on the US government to take immediate action to reform mass surveillance. We agree. You can take action today by signing our petition to tell President Obama to amend Executive Order 12333 to prohibit mass surveillance of people around the world.