Social media posts don't do anything. A lot of people are latching onto one side of that coin - they are futile because they have no ramifications. On the other side, which they like to ignore, there's absolutely no reason to get up in arms over a post because the posts don't do anything. To get upset about someone's profile picture or status is to say those do something - they make you upset.

As for if we should be up in arms about Beirut, probably, but we're not. We're not really even up in arms about France. We're making more noise, but just like the last terrorist attack, we probably won't do anything. If anything gets done any time soon, it was very likely already in the pipes and rode the coattails of this tragedy to passing.

As for your final paragraph, I don't think the messages of social media change with these tragedies, just the language of those messages. People are generally still in character with what they say, but they wrap it in this new common vernacular. Your religious friends still proselytize, your militant friends still call for intervention, you insecure friends still seek attention. It's just a new way for people to tell the old story of who they are.

If you want a real challenge on social media, try to see past these topical conversations and into the person who's having them - that's what people are really asking you to do. These conversations don't matter to the people in France, they matter only to the people directly in your life, and in that way they are worth having.