If you own a smart device, such as a voice-assisted speaker, a smart TV or fridge, you'll know it's listening all the time.

Even when you're not using the device directly, it's listening out for a so-called wake word — like "OK Google" for your Google Home, or "Alexa!" on an Amazon device, or "Hey Siri" on Apple.

Without that function, there would be no point in them. (Hmm… note to self.)

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But as they're constantly listening for instructions from you, they also hear everything else you do — from washing the dishes to random conversations, or intimate information, like secrets or a health diagnosis.

Even your ablutions.

Every cough, fart, and "Darling, I love you" gets sucked up and sent in seconds to servers for analysis to check whether you've expressed an instruction to your device, or whether you're just living your life.

And most of that data — private data — gets logged.

Existing powers

It's small wonder that law enforcement agencies are keen to get their hands on the data to help them solve crimes and find missing people. Because all that pulled together can help them build a picture of your movements — or those of a criminal.

As such, home secretaries from Germany's federal states are discussing plans to give powers to police to seize and analyze data stored on, or via, smart devices.

The uproar has been swift and predictable, with a liberal use of the German word "Wanze." It's nothing more than the German for bug — as in, spying device — but here, with the country's Nazi and Stasi histories, say "Wanze" and all kinds of alarm bells ring.

It's been reported that Hans-Joachim Grote, home secretary for the state of Schleswig-Holstein, has been one of the driving forces behind a new approach to digital data in policing.

But his spokesman, Dirk Hundertmark, told DW there had been "a misunderstanding."

There was no desire for a new law, he said, one that would give new powers to police to seize smart data. And it wasn't about spying on people's kids in their bedrooms.  

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"It's about improving the existing laws to allow police to search and analyze digital media, such as hard drives," said Hundertmark. "But data from smart devices too — with a court order, of course."

Practical policing

For day-to-day policing, all evidence is welcome — if it helps solve a crime or find a missing person.

So the idea that police would want access to data stored by the providers of smart technology is "nothing new," says Carola Jeschke at the office of criminal investigation in the state of Schleswig-Holstein.

And indeed in the USA, smart speaker data from an Amazon Echo device has been admitted as evidence in a murder case.

"If a smart speaker happens to be at the scene of a crime," says Jeschke, "or a place where a missing person was last seen, it can help. The audio data could indicate whether there was more than one person in the room, what their intentions were, whether they put their heating on holiday mode, or ordered groceries."

That's just a snapshot of the depth of smart data.

And all the more reason for concern when a minister's spokesman — namely, Dirk Hundermark — insists that Amazon's Alexa doesn't store data, as he did when we spoke to him.

But they clearly do.

"It's like DNA," says Jeschke, "A criminal leaves digital tracks whether they want to or not."

Invasion of privacy

The problem is, there's still very little detail on the plans being discussed by Germany's federal home secretaries (policing is a state-level matter in Germany) — and little perspective of any more clarity before the autumn when a decision may, or may, not fall.

But there are options.

Law enforcement may want better access to retrograde data — data that's been recorded and stored — and is made available in the event of a crime.

Legislators could alternatively aim to force providers to store certain data, such as is done in telecommunications with data retention laws.

Or they may want to use these devices as real-time bugs to listen in on live situations.

But it can be debated whether or not the country needs new laws for any of that. The laws are purposely kept a little vague to maximize their application to different devices.

"Our position," says Dirk Hensel at the German office of the federal commissioner for data protection, "is that there is no need for new laws at this time because security agencies can already access a lot of data and do a lot with it."

Apart from that, Hensel says the current discussions could lead to a "massive invasion into people's basic rights."

"So, first, we're asking for a moratorium, let's re-evaluate and use what we've got — in any case, crime numbers are in decline," says Hensel.

"But we also need to ask whether any new powers are justified, especially if we're talking about using smart speakers as live bugs. Some people have them in their bedrooms, in intimate spaces, and some aren't even aware that data gets recorded. Let's not forget that the constitution protects a person's privacy in the home," he says.

Germany's constitutional court, says Hensel, has warned against any surveillance measures becoming excessive. Even if it helps catch criminals.

A low threshold        

Digital data has been increasingly useful for law enforcement and other security agencies.

In fact, in Germany, the threshold for police to seize a smartphone is relatively low, according to Dr. Nikolaos Gazeas at the German Lawyers' Association.

Gazeas says such evidence is now among "the most valuable" kind. 

But he says that the plans being discussed by the home secretaries would bring a new quality to policing. But that's not necessarily a positive quality.

"If this data is collected in people's most intimate, private spaces, it should not be allowed to be simply handed over to law enforcement," says Gazeas. "Citizens would be left unprotected and at the mercy of the state."

No one is required under German law to incriminate themselves, he says.

But the home secretaries, says Gazeas, seemed to be playing down the threat.

"It's not as if they just want to 'go with the times,'" says Gazeas. "They want to create an all-encompassing circle of knowledge and that would be a deep invasion of people's privacy."