Trademark infringement and dilution. First the basics: A trademark is any name or graphic image that identifies and distinguishes products or services: a word such as "Kodak," a graphic image such as the "Ask Jeeves" butler, or a combination of elements such as the colors, lettering, and graphics used to distinguish Ebay.com from other online auction sites. Trademark infringement occurs when a second user's use of the trademark is likely to confuse consumers as to the origin of products or services.

The use of a graphic trademark -- for example, the Playboy bunny logo -- to link to the trademark owner's site is sometimes a risky proposition. Unlike the use of a simple word link, a consumer is more likely to be confused into believing that the linked site (the site that owns the graphical trademark) is associated with or endorses the site doing the linking.

EXAMPLE: An X-rated website used the Playboy name and bunny logo to link to the Playboy website. Playboy sued and proved that users of the site may be confused as to whether Playboy sponsored or endorsed the adult site. Playboy also proved that its trademarks would be blurred or tarnished by the association with the adult site. Playboy Enterprises, Inc. v. Universal Tel-A-Talk Inc., 1998 U.S. Dist. LEXIS 17282 (E.D. Pa. 1998).

Copyright infringement. Although it is not a violation of copyright law to create a hyperlink, it is a violation of the law to create a link that contributes to unauthorized copying of a copyrighted work if the linking party knew or had reason to know of the unauthorized copying and encouraged it.

EXAMPLE: A website posted infringing copies of a church's copyrighted handbook at its site. The website was ordered to remove the handbook but subsequently provided links to other sites that contained infringing copies of the handbook. These links were different from traditional hyperlinks, because the website knew and encouraged the use of the links to obtain unauthorized copies. The linking activity constituted contributory copyright infringement. Intellectual Reserve, Inc. v. Utah Lighthouse Ministry, Inc, 75 F. Supp. 2d 1290 (D. Utah 1999).