Electronic Frontier Foundation (EFF) — Headquarters: 815 Eddy Street, San Francisco, CA

Note: The provided excerpt from the EFF's About page discusses the organization's mission, history, and work, but does not include any information about their physical headquarters address. While the source URL is from eff.org/about, the specific text excerpt provided does not contain the address claim. To verify this claim, one would need to access other sections of the EFF website or external sources that explicitly state their headquarters location.

Note: The source is the 'About' page from EFF's website, which contains general information about the organization, its mission, history, and various sections/links. However, the provided excerpt does not include any physical address or headquarters location information. While the source is relevant to EFF, it simply does not address the specific claim about the headquarters address. To verify this claim, one would need to find a source that explicitly states EFF's physical address.