Flash Cookies and Privacy

Soltani, Ashkan; Canty, Shannon; Mayo, Quentin; Thomas, Lauren; Hoofnagle, Chris Jay

doi:10.2139/ssrn.1446862

Download This Paper

Open PDF in Browser

Add Paper to My Library

Flash Cookies and Privacy

8 Pages Posted: 11 Aug 2009

See all articles by Ashkan Soltani

Ashkan Soltani

University of California, Berkeley - School of Information

Chris Jay Hoofnagle

University of California, Berkeley - School of Law; University of California, Berkeley - School of Information

Date Written: August 10, 2009

Abstract

This is a pilot study of the use of 'Flash cookies' by popular websites. We find that more than 50% of the sites in our sample are using flash cookies to store information about the user. Some are using it to 'respawn' or re-instantiate HTTP cookies deleted by the user. Flash cookies often share the same values as HTTP cookies, and are even used on government websites to assign unique values to users. Privacy policies rarely disclose the presence of Flash cookies, and user controls for effectuating privacy preferences are lacking.

Keywords: Privacy, tracking, flash, cookies, local stored objects, usability, online advertising, behavioral targeting, self-help

JEL Classification: D18

Suggested Citation: Suggested Citation

Soltani, Ashkan and Canty, Shannon and Mayo, Quentin and Thomas, Lauren and Hoofnagle, Chris Jay, Flash Cookies and Privacy (August 10, 2009). Available at SSRN: https://ssrn.com/abstract=1446862 or http://dx.doi.org/10.2139/ssrn.1446862