When using third-party advertising such as Google or DoubleClick, reference their usage and include the appropriate links. Google is just one example of many advertising sites.
Local shared objects (LSO) are also referred to as "zombie" or "super" cookies. They are part of Adobe Flash. Quoting from Adobe:
Local shared objects, sometimes referred to as "Flash cookies," are data files that can be created on your computer by the sites you visit. Shared objects are most often used to enhance your web-browsing experience. A website can write a cookie on your computer, and the next time you visit it will load that cookie and its information in a way that provides a more customized experience. For example, you may have asked a site to remember your login name. That information is stored in the cookie and retrieved on your next visit so that the website displays your name in the login field on the site.
The interesting thing about LSO's are that when you delete your cookie cache, the LSO is able to rewrite the cookie. This causes the LSO to be used not only for tracking, but for spyware as well. The only time your site should use Adobe Flash LSO's are when you have created Flash files (.SWF / .FLV) to share with your visitors and these local stored objects should not be abused with the intent on spying upon your site visitors.
A little more information may be found on local shared object.
Children's Online Privacy Protection Act.
Websites that are collecting information from children under the age of thirteen are required to comply with Federal Trade Commission (FTC) Children's Online Privacy Protection Act (COPPA).
COPPA is United States law, however, the U.S. Federal Trade Commission has made it clear that the requirements of COPPA will apply to foreign-operated web sites (referred to as operators) if such sites "are directed to children in the U.S. or knowingly collect information from children in the U.S." per FTC Privacy Initiatives
- COPPA - Children's Online Privacy Protection Act : http://www.coppa.org/
- revised 01 July 2013: http://www.ftc.gov/opa/2013/07/coppa.shtm
- modifications December 2012 : http://www.ftc.gov/opa/2012/12/coppa.shtm
- Bureau of Consumer Protection - FTC : http://www.business.ftc.gov/privacy-and-security/childrens-privacy
- The Children's Online Privacy Protection Act : http://www.ftc.gov/privacy/privacyinitiatives/childrens.html
- COPPA FAQ's : http://www.ftc.gov/privacy/coppafaqs.shtm
- Wikipedia article
Platform for Privacy Preferences (P3P) http://www.w3.org/P3P/
- standards developed by the World Wide Web Consortium (W3C)
A few articles of interest:
- Privacy Lawsuit Targets Net Giants Over ‘Zombie’ Cookies
- Browser Fingerprints Threaten Privacy
- A Primer on Information Theory and Privacy
- Flash Cookies and Privacy
- Federal Trade Commission
- Network Advertising Initiative
- EFF - Best Practices for Online Service Providers
- BBB Security & Privacy - Made Simpler