Sadism and masochism can also be part of BDSM, which stands for bondage and discipline, domination and submission, and sadism and masochism. This has developed into an underground subculture, which holds informal meetings (also called munches) for support, information and learning.
There are events for those who practice BDSM--these are known as play parties. Conventions are also held, for example: the Ohio Leather Fest , TESfest in NYC, Black Rose in Washington DC, and the Folsom Street Fair in San Francisco. While some of these require registration, others like the Folsom Street Fair are public events with a past attendance of over 400,000 people. If attending, expect any combination of demonstrations, classes, vendors, performances, play space and speakers.