On a recent day, the feed of a Tumblr blog called Black Culture featured a drawing of Lupita Nyong’o, a video of a protest at William Paterson University and a text that read, “black lives > white feelings.” The blog FreeQuency Frequently Writes posted a Tweet from Solange Knowles decrying depictions of outspoken women, while another called Soul Revision turned up a post with the hashtags #SeasonOfInconvenience and #BlackLivesMatter.

As protests sparked by a grand jury’s decision not to indict Darren Wilson began spreading nationwide, furor was also growing in cyberspace, in the social-justice halls of Tumblr, a social-blogging platform dominated by users in their teens, 20s and early 30s. Their feeds were vivid mash-ups of articles, GIFs, cleverly labeled images, court documents, smartphone videos, stickers and cartoons, and their posts contained news about Ferguson, along with tidbits about identity, inequality, police abuse, racism, body shaming and more.

“A lot of millennials have been discouraged for a long time,” said Zellie Thomas, 30, creator of Black Culture. “Now, with social media, they feel empowered, like people are hearing their voice. And Tumblr is a great platform for all types of media.”

There are more than 215 million blogs on Tumblr and, according to comScore, an analytics company, 50 percent of Tumblr users are from 15 to 34 years old. The company’s internal surveys show that 64 percent of users say that they care about social causes and look into them on Tumblr. These numbers suggest that millennials, who have long been pigeonholed as an apathetic bunch, have a strong interest in social issues — it’s just hidden from the eyes of their elders.