The American Civil Liberties has filed a complaint with the Homeland Security Department over how agents treat U.S. citizens at checkpoints in Southern Arizona.

The ACLU’s complaint focuses on checkpoints that dot highways in Southern Arizona, mostly near small towns.

Fifteen people in a dozen incidences at six checkpoints complained that Border Patrol agents overstepped their authority and searched their vehicles without having reason to do so.

Guidelines say that agents can ask brief questions about a person’s citizenship but need good legal reason to do anything more at checkpoints.

"One man who objected to questions that had nothing to do with his residence status was at gunpoint forcibly pulled out of his vehicle and almost Tasered by a group of agents in Southern Arizona about a month ago," ACLU lawyer James Lyall said.

In a statement, a Customs and Border Protection spokesman said the agency does not tolerate agent misconduct and investigates all complaints.