A Supreme Court justice pointed to President Trump's use of Twitter during arguments in a challenge to a North Carolina law that forbids registered sex offenders from using social media.
The law, Justice Elena Kagan said, makes it illegal for a group of people to communicate with the president using his favored form of communication
"This has become a crucially important channel of communication," Kagan said.
The justices heard oral arguments Monday in Packingham v. North Carolina.
Lester Packingham is a registered sex offender who posted a statement on Facebook celebrating the dismissal of a traffic ticket.
Police in Durham, N.C., indicted him for breaking the state's 2008 law that bans sex offenders from using social media that allows children to be members, including Facebook, Twitter and Instagram.
Packingham is challenging the law as too broad and a violation of his First Amendment rights.
Questions from Kagan and the three other liberal justices suggested they are concerned the law overly restricts free speech.
It "forecloses some of the most important channels of communication in our society," Justice Sonia Sotomayor said.
Kagan said in addition to blocking a channel of communication with President Trump, the ban also restricts how sex offenders interact with lawmakers and with religious groups.
"These sites have become embedded in our culture as a way to exercise constitutional rights," Kagan said.
Senior Deputy Attorney General Robert Montgomery for North Carolina said sex offenders have alternative ways to express their first amendment rights.
The law, he said, is a protection for children against sex offenders who have a high rate of repeat offenses.
"Our goal is was to protect children from sex offenders and I think that's what I think we were working at doing today," Montgomery told reporters after the hearing.
Conservatives on the court asked few questions.
Chief Justice John Roberts noted the lack of precedent in a case dealing with social media.
Justice Samuel Alito said perhaps the law could be narrowed to impact fewer websites.