NSA whistleblower Edward Snowden’s revelations of mass surveillance by government agencies has made a big impact on investigative journalists, according to a new study.

The survey of 671 journalists, conducted by the US-based Pew Research Center and Columbia University’s Tow Center for Digital Journalism, found that 64% believe that the US government has probably collected data about their communications.

49% said that they have changed the way they store and share potentially sensitive documents in the last year as a result, while 29% have altered the way they communicate with fellow journalists.

However, only 3% have opted not to pursue a particular story due to concerns about electronic surveillance and hacking, although 13% have not reached out to a particular source for those reasons. Just 2% have considered abandoning investigative journalism.

The study quizzed members of trade body Investigative Reporters and Editors (IRE) on their concerns and professional habits in December 2014, using an online survey.

It found that meeting in person rather than communicating by phone or email remains the most popular way journalists try to protect sources: 48% said they have been doing this for more than a year, while a further 11% have started in the last 12 months.

7% of journalists surveyed said they’d been using encryption for email and instant messaging for more than a year, while 8% had started in the last 12 months. Only 3% in total use voice encryption when communicating by phone.

When it comes to protecting their own data, 91% of journalists surveyed now use different passwords for different online accounts, including 15% who have started doing so in the last year.

64% regularly clear their browser history; 72% use enhanced privacy settings on social networks; and 66% turn off the geolocation features in mobile devices, apps and social networks.

Other findings included a lack of confidence in internet service providers, with just 2% of journalists saying they have a lot of confidence that their ISP can protect their data, compared to 27% who had some confidence, and 71% who had “not much or no confidence at all”.

90% said they believed that their ISP would share their data with the US government as part of standard data gathering by the National Security Agency (NSA), while 97% said they believed it would if subpoenaed by the government as part of a criminal investigation.

There was more confidence in the ability of their own news organisations to protect them: 47% said their company was doing enough to protect them and their sources, although 50% said it was not.

To a separate question on whether their organisation had taken new steps to protect them against surveillance and hacking in the last year, 36% said it had not, while 21% said it had. 41% said they had received training from outside sources about ways to protect themselves and their sources.

“In a world of diminishing newsroom resources, some respondents say the issue has not risen to a level where it can be treated as a budgetary priority,” explained the report’s authors Jesse Holcomb, Amy Mitchell and Kristen Purcell.

“Comments also show that while some journalists view these issues as being the responsibility of the IT department and something they do not pay much attention to, others are actively encouraging their organisations to improve.”

That played into a wider finding in the report: that budget cuts are a bigger headache for most investigative journalists than the threat of electronic surveillance.

88% said decreasing newsroom resources was their biggest challenge today, compared to 5% saying legal action against journalists, and 4% saying electronic surveillance. 56% chose legal action as the second biggest challenge, while 28% chose electronic surveillance.

“Overall, these data paint a complex picture in which investigative journalists on the whole feel vulnerable to surveillance and hacking, but not to the degree that most are changing their journalistic practices dramatically or investing energy into figuring out how to do so,” claims the report.

“And nearly all of those surveyed (97%) say that for today’s journalists, the benefits of digital communication like email and cellphones outweigh the risks. Just 3% say the risks outweigh the benefits.”