A new proposal limiting surveillance by drones will be debated by Missouri lawmakers, but the ACLU thinks it may not go far enough.

The bill would require police to get warrants to gather evidence before sending unmanned aircraft over farmland or homes. Doug Bonney, legal director of the local chapter of the ACLU, likes the bill, but says it could be broadened because technology is leading us down a slippery slope.

"Governments are engaging in surveillance of people in their homes and in their yards with cameras fixed to trees or light poles and that kind of thing," says Bonney.

Drones used by law enforcement have come down in price and generally courts have ruled aerial surveillance without a warrant is legal. But Bonney says he's worried that privacy is rapidly being written out of existence and he'll be watching the legislation carefully.

"ACLU watching legislation on surveillance in Missouri" KMBZ, January 4, 2013