It was not until 1890 that Samuel Warren and Louis D. Brandeis wrote “The Right to Privacy,” their groundbreaking Harvard Law Review article. Influential though it was, it came awfully late in the life of the republic.

The word privacy does not appear in the Constitution, and, outside the context of government searches, the document has almost nothing to say about the concept. This was perhaps best demonstrated by how hard the Supreme Court had to work in Griswold v. Connecticut, the 1965 ruling that established a right to marital privacy.

That right, Justice William O. Douglas wrote, was suggested by the First, Third, Fourth, Fifth and Ninth Amendments. The “specific guarantees in the Bill of Rights have penumbras, formed by emanations from those guarantees,” he wrote, in a much-mocked passage.

European courts, by contrast, have Article 8.

In 2004, the European Court of Human Rights relied on it to rule that Princess Caroline of Monaco could block German magazines from publishing pictures of her — quite tame pictures — that had been taken in public. “I believe that the courts have to some extent and under American influence made a fetish of the freedom of the press,” Judge Bostjan M. Zupancic of Slovenia wrote in a concurrence. “It is time that the pendulum swung back to a different kind of balance between what is private and secluded and what is public and unshielded.”

The differing conceptions can have profound consequences. “Europeans are likely to privilege privacy protection over both economic efficiency and speech,” Susan P. Crawford, who teaches Internet law at the University of Michigan, wrote in an e-mail message. “They’re willing to risk huge economic losses and erect trade barriers in order to protect privacy.”

The Italian prosecution would be unimaginable in America. The Communications Decency Act of 1996 leaves online companies free of liability for transmitting most kinds of unlawful material supplied by others. Prosecutions for truthful speech on matters of public interest are almost certainly barred by the First Amendment.

Still, said Marc Rotenberg, executive director of the Electronic Privacy Information Center, there may be something to learn from the Italian episode. “This video was enormously controversial, widely seen and very upsetting,” he said. “Sometimes,” he added, “there are egregious acts and there should be some responsibility.”