1. Other countries marched to show their support for France. The banners, shirts, and posters are to show how they are against what happened during the terrorism.
2. Charlie Hebdo was targeted because the magazine publishers that worked for had pictures mocking Saddam Hussein. The terrorist that invaded the publishers are Cherif and Said Kouachi who were involved with the Al Qaeda group.
3. The other terrorist was Amedy Coulibally. Amedy killed an unarmed police officer who was responding to a traffic incident in the southern Paris suburbs of Montrouge. He also barricaded a Kosher supermarket and killed four people. Charlie Hebdo was determined to show that the magazines could publish what ever they wanted. They did this by publishing a picture of Saddam Hussein holding a "Je Suis Charlie" sign.