American civil liberties groups want politicians to stop blocking people from their social media accounts.

And those politicians include President Donald Trump.

The American Civil Liberties Union, known as the ACLU, filed a lawsuit against the governor of the state of Maine. The group also sent warning letters to the congressional members from the state of Utah.

That comes after the ACLU filed lawsuits against the governors of Kentucky and Maryland in early August. In July, a free speech organization connected with Columbia University in New York City sued President Trump.

The president often uses Twitter to communicate with the American people. But some Twitter users say they have been blocked by Trump for sending tweets he did not like.

Those people can no longer send messages to Trump on Twitter.

That action raises questions about what elected officials can do on their social media pages.

In the past, politicians may have held public meetings to learn the concerns of voters. Now, however, they use Facebook and Twitter to have online conversations with voters.

Anna Thomas is a spokeswoman for the ACLU of Utah.

She said voters see their representatives as available on Twitter and Facebook.

"They're hungry for opportunities to express their opinions," she said. "That includes people who disagree with public officials."

The officials targeted by the lawsuits and warnings so far are all Republicans.

They say they are blocking people who post "hateful and violent content," "spam" and "off-topic comments."

Matt Whitlock is a spokesman for Orrin Hatch, a U.S. senator from Utah. He said people are only blocked after they violate rules.

Whitlock said Hatch's Facebook page should not be used as a platform for "offensive content or misinformation."

Katie Fallow is a lawyer at the Knight First Amendment Institute at Columbia University in New York City. Her organization filed the lawsuit against Trump last month.

She said politicians who choose to use social media "can't pick and choose who [they] hear from."

U.S. courts have not heard cases like these before. But one legal expert said the free-speech advocates like the ACLU probably will be able to make a stronger case than the politicians.

Erwin Chemerinsky is the head of the law school at the University of California – Berkeley. He said the officials may be able to block followers only if they are blocking supporters and critics alike. "It's got to be content-neutral," he said.

While the question of whether politicians can block people from their social media pages may seem minor, one expert says it is quite important.

Amanda Shanor works for the Information Society Project at Yale University's Law School. With more of the political discussion happening online, she said, "it's more important that we know what these rules are."

I'm Dan Friedell.

Dan Friedell adapted this story for Learning English based on reporting by the Associated Press. Hai Do was the editor.