"As founder of the Chilling Effects Clearinghouse, an online resource to help Internet users understand their rights, Seltzer regularly posts cease and desist letters received by Web sites including one recent letter pharmacy chain CVS sent to a Web site called IHeartCVS.com.

The letter claimed IHeartCVS had infringed on intellectual property rights by posting "links to in-store redeemable CVS coupons." The Web site was asked to "destroy any and all unauthorized reproductions of CVS' intellectual property."

"I'd argue that links to pages on CVS' site are not infringements of copyright," Seltzer said."