The world goes on after the terrible attacks in Paris, even as we mourn, rage, and worry.

In the digital age, that means companies had to decide how to react--almost in real-time. The New York Times made its digital product free to nonsubscribers who wanted to learn about the tragedy. Saturday Night Live's Cecily Strong opened the week's show with a brief message of solidarity, speaking in both English and (to my nonfluent ear, anyway) excellent French.

Other brands had to make bigger decisions. Here's how a few of the most iconic responded. (Let me know if I missed a compelling response by contacting me here.)

1. Facebook (news)

With a billion active users every day--many millions of them in France--Facebook was overwhelmed with people sharing thoughts (and in some cases, news) about the cowardly attacks. It was on Facebook that one of the initial and most harrowing first-person accounts by a victim was posted. Isobel Bowdery, a 22-year-old South African woman who was inside the Bataclan concert center when terrorists attacked, wrote:

It wasn't just a terrorist attack, it was a massacre. Dozens of people were shot right infront of me. Pools of blood filled the floor. Cries of grown men who held their girlfriends dead bodies pierced the small music venue. Futures demolished, families heartbroken. in an instant. Shocked and alone, I pretended to be dead for over an hour, lying among people who could see their loved ones motionless.. Holding my breath, trying to not move, not cry--not giving those men the fear they longed to see...

2. Facebook (flags of solidarity)

Facebook enabled a feature that allowed people to overlay a French flag on their profile photos (with a default option for the overlay to be only temporary). This is the second time Facebook has enabled this feature--the first being after the U.S. Supreme Court ruled earlier this year that marriage equality is a fundamental right.

3. Facebook (check-in)

Finally, and somewhat controversially as it turns out, Facebook enabled a check-in feature that let people who had been in Paris register as "safe."

This was the first time Facebook has enabled this feature in the wake of anything other than a natural disaster, and that opened the social network to criticism that it pays attention only to Western tragedies. As Al Jazeera reported:

Social media users took issue with the decision and expressed anger that it had been used after the attacks in France, but not in Beirut where suicide bombers had killed at least 43 people a day earlier. Both attacks were claimed by the Islamic State of Iraq and the Levant (ISIL) group.

4. Google (and Skype)

In the wake of the attacks, Google announced that it was making all calls to France free through the use of its Hangouts feature. Skype made the same type of announcement, with all communication to and from France being offered for free for the next few days.

5. YouTube

At the same time, YouTube, which is owned by Google, changed its logo to one with blue, white, and red stripes, like the French flag.

6. Amazon

As of 7 a.m. Monday, Amazon's home page still has been covered with a simple image of a French flag against a blue background, and the word "Solidarite." This is a simple gesture, but one imagines it has some financial impact, since the front page of Amazon has to be the source of quite a bit of revenue for the company.

Browsing through the different front pages on Amazon's sites around the world, I found the same message on the pages for France, Germany, the United Kingdom, Canada, and Italy--but not for China, Japan, or Mexico, for example.