A well-known German political and tech news website has received (English translation here ) a nearly unprecedented letter from the German Federal Public Prosecutor, saying that two of the site’s top editors are being investigated for treason after having published secret government documents earlier this year.

Netzpolitik.org’s two earlier articles (one in February and another in April) detailed the proposed surveillance expansion of social networks by the Federal Office for the Protection of the Constitution, an intelligence agency.

"We don’t know if we should cry or not," Markus Beckedahl, the site’s editor-in-chief, told Ars from Berlin. He was specifically named as one of the targets of the investigation, along with Andre Meister, another top editor. A third target, named "Unknown," was also mentioned in the letter.

"We leaked some internal documents of the secret service of Germany in the spring, documenting that they are building up a mass surveillance on social networks with lots of new jobs and new capabilities," Beckedahl added. "And this wasn’t in public and there wasn’t a debate, two years after Snowden, whether to have more control of secret services."

Earlier this month, Beckedahl wrote in English that German public radio had reported charges had been filed in relation to the earlier articles, but he was not sure if the charges were against the source of the leak, or against his publication. Now, after having received the notification, he has official confirmation that at this stage it is just an investigation and not criminal charges yet.

"The only thing we can do at the moment is to raise awareness to say that it’s a battle of press freedom," Beckedahl said, adding that the last time German journalists were charged with treason was in 1962.

"We see it as attempts to threaten us and others," he added. "Until today we thought it was a nice summer and we can go to beaches and have fun, but we have to ask ourselves what we would do if they send us to prison? We don’t know, we will see."

According to the BBC, the maximum sentence for treason in Germany is 15 years in prison, but a judge can expand this to a longer sentence.

The story has been huge news in German press and has crippled the site temporarily. On Twitter, Beckedahl has pointed readers to the Internet Archive and to pastebin.com for the time being.

He also pointed out that the German government gave the site a prize earlier this year as part of the "Land of Ideas" competition. The site also won the prestigious Grimme-Preis, a German media award, in 2014.