Google explained their decision on their official blog:
Last Wednesday Sony began contacting a number of companies, including Google, to ask if we’d be able to make their movie, “The Interview,” available online. We’d had a similar thought and were eager to help—though given everything that’s happened, the security implications were very much at the front of our minds.
Of course it was tempting to hope that something else would happen to ensure this movie saw the light of day. But after discussing all the issues, Sony and Google agreed that we could not sit on the sidelines and allow a handful of people to determine the limits of free speech in another country (however silly the content might be).
Here is Microsoft’s statement:
In the United States, freedom of expression is a fundamental principle that is protected by law. Our Constitution guarantees for each person the right to decide what books to read, what movies to watch, and even what games to play. In the 21st Century, there is no more important place for that right to be exercised than on the Internet. After substantial thought, we decided to stand up with Sony and work with others to ensure that freedom of expression triumphs over cyber-terrorism.
We of course appreciate that there are varied views regarding this film. That’s true of many works and many issues. We’re not endorsing this movie or any other. We are supporting the Constitutional right of free expression, and we hope that by acting together, we will help deter other attacks.
You can rent The Interview for $5.99 or buy it for $14.99. In addition to Google Play and YouTube Movies, you can make this purchase through the website https://www.seetheinterview.com/. It will also be available on the Xbox console, Windows Phone, or PC or tablet running Windows 8 or 8.1.