Cancer
Cancer is 4chan-born internet slang for content, users, or trends deemed to be ruining an online community, most often deployed by /b/ regulars against posters they see as newcomers or outsiders. The term surfaced in early 2007 during a GunzFactor forum thread on 4chan's Habbo Hotel raid and later spawned stock replies like 'That Post Gave Me Cancer.'
Overview
Cancer is 4chan slang used to label anything a poster thinks is ruining internet culture, from forced memes and meme merchandise to newer users who don't fit in3. The metaphor works because it is medical, calling a thread or a group of posters cancer implies contamination that spreads and degrades whatever it touches.
The word itself has old roots. English took cancer from Latin, which pulled it from Greek karkinos, meaning both 'crab' and 'tumor,' a name Hippocrates and Galen used after noticing that some tumors with swollen surrounding veins looked like crabs2. On /b/, that clinical weight is the whole appeal, calling something cancer signals not just dislike but pollution.
How It Spread
How to Use This Meme
Cancer typically works as a noun aimed at a target: 'this thread is cancer,' 'normies are cancer,' 'forced memes are cancer.' The 'That Post Gave Me Cancer' macro pairs the 60s Spider-Man reaction face with any post the user wants to dunk on and functions as a one-image reply. Common convention is to reserve the term for content the poster sees as low-effort, out of place, or imported from a lower-status corner of the web.