Pop star Justin Timberlake may have run afoul of Tennessee election law when he posted a photo of himself in a polling station on social media, authorities said on Tuesday (October 25), the latest controversy over so-called ballot selfies.

Timberlake, 35, posted the photo on Monday and said in the caption that he had traveled from Los Angeles to his hometown of Memphis to take part in early voting ahead of the Nov. 8 election.

“Get out and VOTE! #exerciseyourrighttovote,” Timberlake said in part of the photo’s caption, which was posted on Instagram, a social media site where he has over 37 million followers.

The problem for Timberlake is that Tennessee law prohibits voters from recording or taking photographs or videos while inside a polling station.

The Shelby County, Tennessee district attorney’s office on Tuesday said it was aware of a possible violation of state election law and was reviewing the matter.

A person convicted of the violation can be sentenced to up to 30 days in jail and fined $50, the office said.

A representative for Timberlake did not respond to requests for comment.

The proliferation of cellphone cameras and social media has created conflicts in states that have laws against the taking of photos inside polling booths and sharing photos of marked ballots.

The laws, which in some cases predate the social media age, are intended to prevent voter intimidation and any slowing of the voting process.

On Monday (October 24), a federal court sided with a Michigan man who said the law there that bans voters from taking pictures of their marked ballots and sharing them on social media violated his constitutional right to free speech. In response, the court halted enforcement of the law.

In Colorado, two voters filed a federal lawsuit on Monday seeking to overturn a state law there that criminalized the showing of a completed ballot to others, arguing that the ban was unconstitutional.