Can you listen to cell phone calls with a scanner?

Last Updated on May 14, 2023 by Dave Farquhar

Can you listen to cell phone calls with a scanner? Can someone listen to your cell phone calls with a scanner? Depending on who you are, I have good news and bad news.

It’s always been possible to listen to analog cell phone calls with a cheap police scanner. But modern cell phones, including smartphones, are digital and encrypted, so listening to them requires costlier equipment like a Stingray device, limiting cell phone snooping to government agencies and others with huge budgets.

The 90s scare

Can you listen to cell phone calls with a scanner
In the 90s, it was fairly common knowledge that you could listen to phone calls with an inexpensive police scanner like this one.

In the 1990s, word got out that it was possible to listen to phone conversations with an ordinary police scanner you could buy at Radio Shack for around $100. And in those days, it was just as easy to find a Radio Shack as it was a McDonald’s or Subway. I remember my dad would rarely talk on a cordless phone because of this. I only ever saw him use one once. And he wasn’t too happy that I would use one and think nothing of it.

Oddly, although he was unwilling to talk about mundane things on a cordless phone, he thought nothing of talking about medical information on his cell phone. Cellular phones were also analog in those days. That meant it was also possible to pick up cell phone calls on a police scanner. I guess no one ever mentioned that to him.

I can remember sometime around 2005, driving around with a friend chasing trains. We’d listen to train dispatchers on his police scanner to find out where the trains would be. He drove and I ran the scanner. I locked in on some guy’s cell phone conversation. I don’t remember what he was talking about, but I remember thinking this shouldn’t still be possible. After about a minute, my friend asked me why we were listening to that, and I resumed my scanning duty.

But because it used to be possible, rumors persist that it may still be possible to listen to cell phone calls with a scanner.

The digital transition

I clung to an ancient analog cell phone long after it was cool, just because it was more reliable and it sounded better. Early digital cell phones sounded terrible. Besides, if someone wanted to listen to me walking someone through connecting tape drives to Windows servers, maybe they’d learn something. But eventually the industry moved to all-digital cellular networks because it allowed other things, like Internet on our phones. We take that for granted now.

That means it’s digital, and it’s encrypted. Encryption means scrambling a message so only the person on the receiving end can descramble it. That means your neighbor can’t listen to your cell phone calls with a police scanner anymore. Listening to cell phone conversations is certainly possible, but it requires more expensive equipment and a much higher degree of skill than using a police scanner.

The biggest telltale sign of the neighborhood mad scientist trying to listen to your calls would be your mobile phone degrading to 3G or 2G or lower, which have weaker encryption that they probably can break. But this is more the stuff of theory than practicality, due to the cost involved.

There are still some parts of the phone network that sometimes get converted to analog and transmitted, so a nosy neighbor with a police scanner can still pick up parts of calls occasionally. But there’s no specific way for a nosy neighbor with a scanner to target you precisely.

Can police listen in on cell phone calls?

Use of Stingray devices by local law enforcement is controversial because it allows them to listen to phone conversations without a search warrant. Since I work in computer security and my clients’ security issues are none of the police’s business, I try to use teleconferencing apps like Skype and Zoom to discuss sensitive information.

Stingrays work by simulating an ordinary cell phone tower, so cell phones connect to that device rather than directly to a cell provider’s network. The Stingray also has enough information that it’s able to decrypt the phone conversation, though it may not happen exactly in realtime. This allows the police or other law enforcement to listen in. The Stingray relays the information so your call still works, and in theory you’re not aware it’s happening.

I don’t have a problem with Stingrays being used on specific individuals who are subject to a criminal investigation, with a search warrant, similar to the way phone taps used to be used. What I don’t like is Stingrays being used to scoop up all conversations in an area, as this circumvents due process.

Can you get in trouble for listening to a police scanner?

The public airwaves belong to everybody, so there is nothing illegal about listening to the airwaves. There’s also no way for anyone to detect you’re doing it, since a police scanner is just a radio. It listens on different frequencies than the radio in your car, but it’s still a radio.

If someone wants to use the public airwaves and doesn’t want you listening to it, it’s their responsibility to scramble the signal. Today the phone companies do that for us by encrypting our phone conversations.

There’s nothing wrong with listening to the local police and fire department on a scanner. Journalists did it for the entire 20th century, and that was how they covered the criminal justice beat. The famous photojournalist Weege used to sleep with a police scanner by his bed. He trained himself to get up when he heard certain things and rush to the scene of an event in the middle of the night to get the shots that propelled him to immortality.

Can scanners listen to cordless phones?

Scanners can’t listen to modern cordless phones, specifically, DECT 6.0 phones. With older standards, it’s hit and miss. Some less expensive cordless phones from recent decades didn’t scramble their signals. These tended to be low-budget phones, but people would buy them because they were cheap.

Many cordless phones sold since the mid 1990s did scramble their signals. But not all. Attrition has certainly reduced the number of cordless phones transmitting on public airwaves since the early 90s, however. More and more people are ditching their landlines, and those who do still have landlines find DECT 6.0 phones work better than their old phones did.

Can you listen to cell phone calls with a scanner: In conclusion

So, can you listen to cell phone calls with a scanner? Can your neighbor listen to your cell phone calls with a scanner? Not anymore. If you have a really old cordless phone, they can pick that up, but that’s yet another reason to upgrade to a DECT 6.0 phone if you still have a landline of some sort. DECT 6.0 is digital, encrypted, and doesn’t interfere with wifi.

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