A survey by the writers’ organization PEN American Center has found that a large majority of its members are deeply concerned about recent revelations regarding the extent of government surveillance of email and phone records, with more than a quarter saying that they have avoided, or are seriously considering avoiding, controversial topics in their work.

The findings show that writers consider freedom of expression under threat in the United States, with 73 percent of respondents saying they have “never been as worried about privacy rights and freedom of the press as they are today.” The survey, to be released on Monday night, was conducted online with 528 PEN members from a membership of more than 6,000 fiction and nonfiction writers, editors, translators and agents.

Smaller percentages of those surveyed described already changing their day-to-day behavior: 28 percent said they had “curtailed or avoided activities on social media,” with another 12 percent saying they had seriously considered doing it; similar percentages said they had steered clear of certain topics in phone calls or email (24 percent had done so; 9 percent had seriously considered it).

Sixteen percent reported that they had avoided writing or speaking on a particular topic, with another 11 percent saying that they had seriously considered doing so.