Mainstream Marketing Services, Inc. v. Federal Trade Commission

The FTC and FCC (defendants) jointly created a national do-not-call registry letting individuals block unsolicited commercial telemarketing calls, requiring telemarketers to pay a fee to access the list and remove registered numbers, while exempting charitable and political fundraising calls and allowing calls to registered numbers where the caller had an existing relationship or written permission. Mainstream Marketing Services (plaintiff) challenged the regulations' constitutionality, and the district court agreed they violated the First Amendment, enjoining their implementation; the FTC appealed that injunction.