US law has remarkably little to say about mass surveillance in public, a failure which has allowed the surveillance to grow at an alarming rate -- a rate that is only set to increase. This article proposes 'Privacy Impact Notices' (PINS) -- modeled on Environmental Impact Statements -- as an initial solution to this problem.Data collection in public (and in the home via public spaces) resembles an externality imposed on the person whose privacy is reduced involuntarily; it can also be seen as a market failure caused by an information asymmetry. Current doctrinal legal tools available to respond to the deployment of mass surveillance technologies are limited and inadequate. The article proposes that -- as a first step towards figuring out how to understand, value, and ultimately regulate this mass-privacy-destroying behavior -- we should borrow from the environmental movement and require anyone planning a large-scale public data collection program to file a Privacy Impact Notice (PIN). The PIN proposal is contrasted to the existing much more limited federal privacy analysis requirement, known as Privacy Impact Assessments. The bulk of the article then explains how PINs would work and defends the idea against three predictable critiques (the claim that there is a First Amendment right to data collection, the claim that EISs are a poor policy tool not worthy of emulation, and the claim that notice-based regimes are in general worthless). It argues that PINs have applications to surveillance and data-collection in online public spaces such as Facebook, Twitter, and other virtual spaces. It also considers what the PINs proposal would have to offer towards addressing the now-notorious problem of the NSA’s drift-net surveillance of telephone conversations, emails, and web-based communications. Modeling mass surveillance disclosure regulations on an updated form of environmental impact statement will help protect everyone’s privacy: Mandating disclosure and impact analysis by those proposing to watch us in and through public spaces will enable an informed conversation about privacy in public. Additionally, the need to build consideration of the consequences of surveillance into project planning, as well as the danger of bad publicity arising from excessive surveillance proposals, will act as a counterweight to the adoption of mass data collection projects, just as it did in the environmental context. In the long run, well-crafted disclosure and analysis rules could pave the way for more systematic protection for privacy -- as it did in the environmental context. Effective US regulation of mass surveillance will require that we know a great deal about who and what is being recorded and about the costs and benefits of personal information acquisition and uses. At present we know relatively little about how to measure these; a privacy equivalent of environmental impact statements will not only provide case studies, but occasions to grow expertise.