1987—In 1986, the Supreme Court ruled in California v. Ciraolo that a person growing marijuana in his back yard does not have a reasonable expectation of privacy that protects his premises against inspection by police lawfully operating an aircraft at an altitude of 1,000 feet. Exercising the illogic that will earn her an appointment by President Clinton to the Eleventh Circuit in 1993, Florida justice Rosemary Barkett (in State v. Riley) rules that surveillance of a back-yard greenhouse by a helicopter lawfully flying at 400 feet violates the Fourth Amendment because “[s]urveillance by helicopter is particularly likely to unreasonably intrude upon private activities.”
But the relevant question, as the Supreme Court makes clear in reversing Barkett (in Florida v. Riley), is whether the defendant had a reasonable expectation of privacy in the first place, and that question turns, under Ciraolo, on whether “helicopters flying at 400 feet are sufficiently rare in this country to lend substance to [the defendant’s] claim that he reasonably anticipated that his greenhouse would not be subject to observation from that altitude.”
2019—A Second Circuit panel rules (in Knight First Amendment Institute v. Trump) that President Trump “engaged in unconstitutional viewpoint discrimination by utilizing Twitter’s ‘blocking’ function to limit certain users’ access to his social media account, which is otherwise open to the public at large, because he disagrees with their speech.” The panel’s ruling rests on its determination that Trump’s Twitter account is a “public forum” for purposes of First Amendment analysis.
But as Harvard law professor Noah Feldman explains, the panel’s decision “rests on a conceptual confusion that has serious negative implications for the freedom of speech.” Far from being a public forum, Trump’s Twitter account is “property controlled by Twitter Inc.,” so it’s Twitter, not the First Amendment, that governs speech on its property.