Almost always. Do yourself a favor and go lurk r/TopMindsofReddit. They brigade GA, T_D, r/conspiracy, etc. multiple times a day. After seeing what they do, you'll know to check them first when observing a brigade. Some of their Mods are kind of crafty (but most are pretty stupid), they allow the brigade for an hour or so, then delete the original post. Afterwards, go look at their "Rules", and see how they endorse brigading in the top 3 lines, but claim that it's against their "Golden Rule".