The massive hack has raised questions about First Amendment rights, privacy and cyberwarfare. But there's a subtler issue at play when we look at all the news stories that have come from hacked inboxes: Why do we put this stuff in email?

Most of the news stories that came out of the Sony hack were based on info from the email inboxes of Sony executives. Sony Pictures

Every summer, Coye Cheshire teaches a workshop to incoming grad students on how to be smart and careful on social media.

The class, held in the School of Information at the University of California, Berkeley, involves letting students know the repercussions of posting things on networks like Facebook and Twitter. But Cheshire doesn't mention an online medium even more basic than social media: email.

"We sort of treat email as a given," said Cheshire. But after the high-profile hack against Sony Pictures Entertainment, which resulted in a leak of tens of thousands of internal emails, financial documents and other items, will he be sure to mention email specifically when he teaches the workshop again next summer?

"Absolutely," he said.

That's just one of the many impacts of the devastating hack, which has already spurred questions about everything from First Amendment rights to cyberwarfare to journalistic ethics. Looking past the marquee headlines, there's a subtler effect: As self-preservation kicks in, people may try to ensure their digital paper trails don't make them vulnerable targets.

The hack, revealed in late November, was carried out by a group that US authorities say is linked to North Korea. That country was upset by the "The Interview," a movie from Sony Pictures starring Seth Rogen and James Franco, about an assassination attempt on North Korean leader Kim Jong-un. Sony on Wednesday announced it was canceling the release of the movie amid threats of terrorism, though on Friday it said a release may still happen.

Inside the company, the hack has been devastating: Amy Pascal, head of Sony's film division and one of the most prominent women in Hollywood, watched as her email inbox was opened to the world and her emails made available for anyone to read. Among the trove of missives: an offensive joke shared with producer Scott Rudin about President Obama's taste in movies. Both of them quickly apologized.

Messages ranging from discussion about Facebook CEO Mark Zuckerberg to new movie ideas to even a script for the latest James Bond film were dumped onto the Internet. And they were revealed by media outlets pouring over thousands of emails from the inboxes of Sony executives.

Read more:

The peculiar star of the Sony hack: Email