You make the call : the FTC's telemarketing sales rule.

Bibliographic Details
Corporate Author:	United States. Federal Trade Commission. Division of Consumer and Business Education
Format:	Government Document Book
Language:	English
Published:	[Washington, D.C.] : Federal Trade Commission, Bureau of Consumer Protection, Division of Consumer and Business Education, [2008]
Series:	FTC facts for consumers.
Subjects:	Telemarketing > Law and legislation > United States.
Online Access:	https://purl.fdlp.gov/GPO/LPS105062

Description
Item Description:	Title from title screen (viewed on Nov. 5, 2008). "June 2008." Electronic resource.
Physical Description:	4 unnumbered pages : digital, PDF file.
Format:	Mode of access: Internet from the FTC web site. Address as of 11/5/08: http://www.ftc.gov/bcp/edu/pubs/consumer/telemarketing/tel13.pdf ; current access available via PURL.