If you've been on Facebook in the past 24 hours then you may have noticed that more and more people are switching out their profile pictures for a photo of a red square with a pink equal sign.

What does this mean, you ask?

The image is the symbol for a social media campaign pushing for marriage equality in light of thetwo arguments heard by the Supreme Court this week centered on the issue of gay marriage. The sign is actually a variation of the Human Rights Campaign logo, a pro-gay rights organization, which is a blue square with a yellow equal sign. However, once the HRC started promoting the red logo for its gay marriage campaign, it spread like wild fire all over the Internet.

According to Fred Saiz, the HRC Vice President of Communication, the image has been seen by 10 million people on Facebook. The image was first posted at 1 p.m. ET on Monday and since then Saiz say it has "snowballed" into a bigger deal than the HRC expected, he told CNN. The image was shared 43,000 times on Facebook while a number of people have saved the image as their own default picture at the HRC's urging.

"It has caught us off guard, to be honest with you," Saiz said. "It has taken off like wild fire."

He added that the social media's reaction to the emblem is "unprecedented."

"You always hope that these things will capture the imagination of those that see it," he said. "I think what you can't predict and plan for how individuals with a bigger reach than your own are going to make your reach exponential in nature."

In the first of two days of hearings on cases that have the potential to change America's law on same-sex marriage, Justice Anthony Kennedy, who is considered the likely deciding vote, questioned whether justices should even be hearing the issue.