How the Sony hack panic has changed Hollywood

There's no question that the hack attack on Sony has wrought havoc on the studio. But it's not just Sony; executives across Hollywood are changing their behavior in the wake of the shocking exchanges revealed in the leaked emails.

Here are five ways sources say the industry has already changed.

Everyone is searching correspondence with Sony

Beyond the embarrassing leaked correspondence between producer Scott Rudin and Sony studio Co-Chairman Amy Pascal (read more about that here), even executives at rival studios realize they could be embarrassed by leaked emails.

A number of sources tell me that anyone's who's done business with Sony is searching their email archive for "" and reading any emails that could potentially appear online.

I'm also hearing that a number of people, including Amy Pascal, are making pre-emptive phone calls to apologize to people who might be offended if more emails get out.

No more e-mail. Real business is now done on the phone

Over the past decade, email replaced the phone as the primary way business was done in Hollywood.

There's no doubt, reading the exchanges between Pascal and Rudin, that if they trusted their correspondent, they didn't worry about emails being forwarded, so people had the kind of casual conversations over email that they'd previously only have in person.

No longer. One source said that even in the past two weeks the emails flying around have "dried up." Now people are treating email more like a letter: A more formal, thought-out correspondence. And now people are writing not just for the audience of the people they're writing to, but with an awareness that the whole world might be able to read it.

Sony is at a disadvantage in negotiations going forward.

Never before has there been such transparency about exactly how much a studio pays, and about how they handle negotiations.

This puts Sony at a disadvantage going forward. The next time an agent is negotiating a contract, they'll know if Sony's first offer is usually 50 percent less than where contracts land, or what perks the studio has a track record of folding on. We can bet that agents are digging through those emails.

Read MoreOne possible reason Scott Rudin berated Angelina Jolie

A hack at another studio would also reveal awful stuff.

Many in Hollywood are saying that even though the leaked emails make Sony execs seem awful, the studio just got unlucky.

The consensus seems to be that while Sony has some big personalities, they're not really worse than anyone else, and that if other studios were hacked we'd know about different gaffes, but they would likely be equally embarrassing.

The other studios are surely working to beef up security and keeping their fingers crossed they don't suffer the same fate.

Read MoreSony hack forces production shutdown

Which leads to...

Hollywood hates the press for publishing the e-mails

A number of executives have said they don't understand why the media is publishing stolen property. (In fact they've already asked that outlets stop publishing leaked material.)

Judd Apatow expressed this frustration in a tweet: "Releasing private Sony emails to hurt people is the same as releasing nude photos of Jennifer Lawrence. Why are they OK to print?"