California legislators have filed a Freedom of Information Act request to learn what federal immigration authorities are up to in their state.

The request was filed this week by California Assembly Speaker Anthony Rendon and Senate President Pro Tem Kevin De Leon, both Democrats, for “information about recent Department of Homeland Security policies and Immigration and Customs Enforcement activities.”

Federal authorities appear to be cracking down on immigration with a recent “surge in enforcement activities,” the lawmakers said in a statement. But federal authorities have provided “limited information,” despite repeated requests, the statement continued. California is home to 5.4 million non-citizen immigrants, and almost half of all children in the state have at least one parent who is an immigrant.

“When the safety of Californians is at stake, we must demand greater transparency, with the backing of federal courts if necessary,” the lawmakers said. “The lives and physical safety of many thousands of Californians —citizens and immigrants, documented and undocumented — depend upon knowing this information.”