Black Twitter is a loosely defined community of Twitter users who can be mobilized for activist means but just as often closely analyze, poke fun at, and bond over the black experience in America. The community is instrumental in adding context to online narratives about race and is also generally acknowledged to be the principal source of Twitter memes that are actually funny. When Black Twitter coalesces around a common enemy, the resulting roasts are legendary.

The demystification of “Black Twitter”
When it comes to trending topics on Twitter, some things really are black and white. 
Time on your hands? Twitter puts it in black and white
Now trending on Twitter: #blackpeoplehobbies and #whitepeoplehobbies.