By Alex Walker, Consumer Content Manager & Robert D’Onofrio, Data Editor

The U.S. Supreme Court overturned the Defense of Marriage Act on Wednesday, and Facebook was the place for colorful conversation with more than 15 million interactions – that’s posts, comments and likes – among Americans who were sharing on Facebook. Globally, more than 25 million pictures were changed – a million more than on Mother’s Day this year.

Supreme Court Defense of Marriage Act (DOMA) Decision on Facebook

Approximately 70% of people on Facebook in the U.S. are connected to a friend who has expressly identified themselves as gay, lesbian or bisexual on their timeline

Related terms around the Court’s pair of landmark decisions had more than four million mentions in posts by the end of Wednesday. “DOMA” was the most talked-about term in the outpouring of emotion and reaction. “Unconstitutional” had the largest percentage increase in mentions, spiking nearly 60,000% by mid-morning. Posts that included the phrases “struck down” and “Prop 8” also saw exponential spikes.

In total, Facebook looked at the top 10 terms in conversations relevant to the Court’s rulings, and found more than 1.5 million mentions from 6am to 8am PDT/9am to 11am EDT. Two hours later, that number had doubled to three million mentions, and topped four million mentions by 1pm PDT/4pm EDT Wednesday.

Supreme Court Defense of Marriage Act (DOMA) Decision on Facebook

Actor Ben Affleck was among the celebrities who joined the conversation on Facebook

Celebrity supporters of same-sex marriage were vocal on Facebook, too. Actor Leonardo DiCaprio wrote, “Historic day. Well done #SCOTUS.” Pop star Lady Gaga chimed in with the post, “We stand tall today. #DomaStruckDown.” Actors Ben Affleck and George Takei also affirmed their support of the Court’s decision to overturn DOMA. Some are also using the hashtag #PrideConnectsUs to express their feelings, including musician Ke$ha and TV actress and host Maria Menounos.

Supreme Court Defense of Marriage Act (DOMA) Decision on Facebook

Heat map of Facebook users expressing happiness around the time of the Supreme Court decision Wednesday*

People on Facebook across the U.S. expressed their happiness with the ruling in timeline posts. California, where many Proposition 8 opponents were awaiting the Court’s decision, ranked highest in happiness mentions.

*We have edited this language to be more precise that the expression of people’s happiness as demonstrated on the map was taken around the time of the SCOTUS decision regarding DOMA.