Facebook isn't all about baby pictures, birthday greetings and amusing memes.
People also turn to the social network to delve into serious subjects such as terrorism, marriage equality and politics, according to Facebook's release Wednesday of the site's most popular topics worldwide in 2015.
With more than 1 billion users globally, Facebook serves as a window to the world, revealing the passions of its audience.
"The moments we shared in 2015 affected us all," Facebook said on its Year in Review. "They shocked, moved and inspired us to take action. They connected us."
Other topics that moved Facebook users this past year were the legalization of same-sex marriage in the US and Ireland, the battle against ISIS, the Charlie Hebdo attack in Paris, the protests in Baltimore over alleged police brutality, and the Charleston massacre and ensuing Confederate flag debate. In the US, Facebook users also were hooked by the upcoming movie "Star Wars: The Force Awakens," Planned Parenthood and the Super Bowl.
Year in Review also drilled down to more specific items, such as the entertainers, movies and TV shows most discussed on Facebook.
Among the entertainers at the top of the heap were singers Ed Sheeran, Taylor Swift, Kanye West, Nicky Jam and Wiz Khalifa. The movies most discussed included "Star Wars: The Force Awakens," "Fast & Furious 7," "Jurassic World," "Avengers: Age of Ultron" and "American Sniper." The TV shows that most snagged Facebook users' attention included "Game of Thrones," "The Walking Dead," "The Daily Show," "Saturday Night Live" and "WWE Raw."
Facebook compiled its Year in Review lists by measuring how often a topic was mentioned in posts between January and December.