Looking at anti-vaccination and non-vaccination online forums, many on motherhood and pregnancy sites, opinions range from dismissal to anger. Some blame the media and the medical industry for blowing the outbreak out of proportion or willfully concealing the real culprit — of which several are posited. There’s frustration for being called ignorant. There’s acceptance that a child might get measles, but there’s also worry that he or she could spread it to vulnerable others.

The messages are a lens into a movement that has grown enormously over the past two decades, but which tends to communicate outside mainstream channels. Not everyone on the anti-vaccine forums is an absolutist — many identify as “delayed” or “selective” vaxxers, meaning they’ve postponed, but haven’t necessarily entirely written off, vaccinations, or have chosen to give their kids only a few shots instead of the full slate.

Here’s a snapshot of those discussions…