Last February, President Barack Obama signed a bill requiring the Federal Aviation Administration to integrate drones into American airspace.

Days earlier, the Supreme Court unanimously agreed police had overstepped their legal authority by planting a GPS tracker on the car of a suspected drug dealer without getting a search warrant.

Those two government actions, made less than a month apart, codify the conflict and complexities testing the balance between personal privacy and the needs of law enforcement in a rapidly changing technological world.

As drones increasingly attract police interest, Alameda County has become something of a beachhead for debate in California. The Sheriff's Office has proposed using surveillance drones for domestic policing. No more than 4.4 pounds, they'd be employed for mission-specific tasks, including crime scene preservation, search-and-rescue operations and hostage situations.

Capt. Tom Madigan of the Alameda County Sheriff's Office told me the devices would take off from within 2,000 feet of a mission – about 6 1/2 football fields – flying at 400 feet to that specific location.

"As with public safety's use of fixed-wing aircraft and helicopters for many years, the use of these devices fall within the confines of the Fourth Amendment," he said, while costing far less to operate.

Aerial views in situations such as hazardous material spills or bomb threats would greatly enhance police response, he added. "Drones can definitely search areas that are tough to get to."

"That invites the very kind of surveillance the sheriff agrees in principle should not occur," counters Linda Lye of the American Civil Liberties Union's Northern California chapter. "The policy proposed takes the form of a sheriff's department general order, which means that he can unilaterally change it down the road."

Lye told me, "Before Alameda County adopts a drone, there need to be privacy safeguards that are a) strong enough and b) enforceable and not subject to unilateral change."

Making policies legally binding can be difficult. You can enact statutes, which some municipalities are attempting, or rely on constitutional law via the courts, which move slowly and always after the fact. That GPS case? The initial arrest was made in 2005. Consider how much technology evolved in those seven years prior to a ruling.

But there's another fly in the ointment. The GPS suspect was indeed a drug dealer. The problem wasn't his guilt; it was the method police used to prove it, and that's the tricky part of the Fourth Amendment.

"The Fourth Amendment says we have the right of privacy even if it means limiting the ability of government to gather evidence of illegal activity," says Erwin Chemerinsky, dean of UC Irvine's School of Law.

"Fourth Amendment protections don't vary on whether we are guilty or innocent," says Lye. "The cost of ensuring our privacy is protected means that occasionally, someone actually guilty of a crime is allowed to go free."

What if a drone tasked for a rescue mission captures images in a citizen's backyard of a meth lab, or worse?

"We cannot turn a blind eye to something like that," Madigan says. "If a child is being abused, should we turn a blind eye?"

"Our perspective is that data collected for one purpose should not be used for other purposes," Lye says. "If you're really worried about the ax murderer captured by the drone, you need to write a very narrow exception, but that's not what we've seen in the sheriff's policy."

The issue in Alameda County remains stalled.

Ultimately, our problem seems twofold. We don't trust government, including law enforcement. Even if a statutory privacy framework is established before deploying a technology, who guarantees that a violator will be punished to the fullest extent of the law? Know any banksters who've gone to jail over the housing meltdown?

Further, we lack any overarching consensus of what information is worth defending and how to defend it. That information and the ways to collect it without physically trespassing on private property are increasing at a geometric rate. Engagement in today's world means leaving digital histories of almost everything we do, all of it easy to archive. The question then becomes: Who can see it? Under what circumstances?

Even there, we're conflicted. In 2010, the 3rd U.S. Circuit Court of Appeals held that law enforcement needed search warrants to gather cellphone location data stored by phone companies. Last August, the 6th U.S. Circuit Court of Appeals ruled that Fourth Amendment protections don't extend to such materials.

Government certainly needs access to data about the movements of credibly dangerous individuals. But what about juveniles suspected of petty crimes? Or paparazzi spying on celebrities? Should parents engaged in child custody battles have access to location data? What about former business partners embroiled in a legal dispute?

Even if the courts address these questions, the definition of privacy in 21st-century America will increasingly, and likely irreversibly, remain illusive.

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