If you see such, Zoe (or anyone else, of course), please hit the REPORT POST button (the little ! in the red triangle in the upper right corner of the post) and let the mods decide. There’s often a fine line between a “friendly joke” about (say) a mental illness, vs hate-speech directed against the disabled. Anyhow, please REPORT it and let the mods decide.
As Liberal has noted, it should be possible to hold civil discussion with people whose ethics are different from yours. A racist, bigot, anti-semite, homophobe, whatever-else who can engage in civil discourse without insulting other posters (or groups) should be able to converse on these Message Boards. Who knows, someone might find the right words to talk them out of their bigotry?