There is no lying, though: the law (39 U.S.C. § 3008) leaves the decision about whether mail is a “pandering advertisement” to “the addressee in his sole discr

There is no lying, though: the law (39 U.S.C. § 3008) leaves the decision about whether mail is a “pandering advertisement” to “the addressee in his sole discretion,” which avoids the First Amendment problems that might arise if the decision were reviewable by a government official, who would then be acting as a censor. It’s been upheld by the Supreme Court; see Rowan v. United States Post Office Department, 397 U.S. 728 (1970), in which the Court held: Both the absoluteness of the citizen’s right under §4009* and its finality are essential; what may not be provocative to one person may well be to another. In operative effect the power of the householder under the statute is unlimited; he may prohibit the mailing of a dry goods catalog because he objects to the contents—or indeed the text of the language touting the merchandise. Congress provided this sweeping power not only to protect privacy but to avoid possible constitutional questions that might arise from vesting the power to make any discretionary evaluation of the material in a governmental official. * Later renumbered to § 3008.