But drawing the line between permissible speech and “true threats” that violate federal law seemed elusive for the court during oral arguments in'Elonis v. United States.

Several justices expressed free speech concerns about the prosecution that resulted from Facebook postings by Anthony Elonis after his wife left him in 2010. Using violent language modeled after rap lyrics, Elonis wrote about killing his wife, shooting random school students and murdering an FBI agent who visited his home.