They were arrested after they refused to obtain alternate nationalities, Voice of America reports. All seven are members of the Reform and Social Guidance Association or al-Islah, a group that resembles the Muslim Brotherhood but is not formally linked to it.
Samer Muscati of Human Rights Watch said the government appears to have little evidence the seven are any threat.
"If you look at the records of these men, they're not specifically identified with any criminal activity," he said. "The only reason they appear to be rounded up is because of their membership in al-Islah."
Mohammed al-Roken, the lawyer representing the seven, said he was barred from meeting with them before the court ruling Thursday. He plans to appeal it.
The UAE is a collection of seven sheikhdoms with hereditary rulers wary of protests. But Christopher Davidson of Durham University told Voice of America that a generous social welfare system fueled by oil revenues has muted dissent.