This guide does not keep anything you type. There are no accounts and no ads. The address you enter never leaves your browser: the guide matches it to a precinct right there, using street ranges prepared ahead of time.
To build an address-to-precinct mapping, public data is used from Census street address ranges and UC Berkeley's Statewide Database counts of registered voters by Census block.
Google Analytics counts visits and lookups using cookies. It never receives your street address.
Google App Engine hosts the website and keeps a standard request log for 30 days that includes the pages requested, when, and the requesting browser and IP address. Street addresses are never in it. Page views and lookups are counted.