Worldwide, Saturday, September 17
In the words of its organizers, Software Freedom Day "is a worldwide celebration of Free and Open Source Software (FOSS). Our goal in this celebration is to educate the worldwide public about the benefits of using high quality FOSS in education, in government, at home, and in business -- in short, everywhere! The non-profit organization Software Freedom International coordinates SFD at a global level, providing support, giveaways and a point of collaboration, but volunteer teams around the world organize the local SFD events to impact their own communities."
There are meeting sites in Boston, around the USA and rest of the world. Check the various schedules for events and times.
Here's Pia Waugh's statement on Free and Open Software's importance for human rights. The basic reference point is, of course, the United Nations accord, "The Universal Declaration of Human Rights."