Fog Makes Police Surveillance Easier and Cheaper — But at What Cost to Your Privacy?

Posted on Sep 16, 2022 by Kristin Hassel

Law enforcement agencies across the US can now track potential suspects and witnesses, without setting off alarm bells, using Fog Reveal. This cheap and effective software from Fog Data Science allows police to use mobile signals to pinpoint any device present in the vicinity of a crime scene

Digital privacy advocates are in uproar, asking if this type of search is even legal in light of the 4th Amendment.

Find out more about what Fog Reveal does, how it works, who can use it, and how you can protect yourself, as we take a deeper look into this easy-to-use surveillance tool.

What Does Fog Reveal Do?

Imagine software that allows you to track anyone, anytime. You can see which establishments they frequent, what time they get to work, and when they typically go home. No sophisticated hardware required — simply log in and check out the scene via an app on your mobile device.

Well, it’s here. Licensed by Fog Data Science, Fog Reveal gives state and local police the power to easily search by location or device information

What results does the app pull up? Where the specific device has been, for how long, and what other devices were in the same location at, or around, that time. A crime investigator’s dream! 

Fog Reveal lets users search signals worldwide.

How Fog Reveal Works

Fog gets its location and device data from its partner company Venntel. This data is acquired from various popular mobile apps that track a person’s location and Advertiser ID (AID) to target them with relevant ads. These include Waze, Starbucks and hundreds of others who may fund innovation by selling their user data to other third parties, like Venntel’s parent company, Gravy Analytics. 

All devices have a unique AID and International Mobile Equipment ID (IMEI) that identify them in different ways. On iOS, your AID is called Identifiers for Advertisers (IDFA), while Android calls it an Android Advertiser ID (AAID). 

With the right software, an AID or IMEI can track mobile devices. Fog Data Science created that software. Fog Reveal can track any mobile device with one of these popular apps installed, as long as the app has permission to access your location and/or serve you targeted ads. 

Fog Data Science built Fog Reveal around AID information, and now has a database of some 250 million unique ‘Fog IDs’ that law enforcement uses to conduct surveillance without a search warrant. 

Fog Reveal’s marketing brochure sells itself as a “four-step investigative process, with no suspects or witnesses”. Here’s how it works.

Fog Reveal’s 4-Step Process

Step 1: Enter the address, date, and time of the incident and start your search.

Step 2: Review smart device signals to uncover devices in the area within the specified timeline.

Step 3: Run a 180-day pattern on devices of interest.

Step 4: Identify bed-downs and other locations of interest for anyone deemed to be a potential suspect or witness.

Who Are Fog’s Clients?

Currently, only state and federal law enforcement entities have the opportunity to use Fog Reveal. The Electronic Frontier Foundation (EFF) obtained documentation showing Fog Reveal has or had contracts with at least 18 clients in local, state, and federal law enforcement. This number isn’t likely to decrease and doesn’t include any law enforcement agencies who use or have used the free trial.

Why Fog Reveal Is Useful to Authorities

For law enforcement, Fog Reveal is the sorcerer’s stone of criminal investigation tools. Easy-to-use, low-cost software that lets you pinpoint any mobile device within the vicinity of a crime scene, without having to hit the streets and chase down leads… it’s a no-brainer.

Law enforcement gets a list of suspicious device IDs and none of their owners even know they’re being tracked. And it doesn’t stop there — Fog Reveal has other compelling use cases for law enforcement agencies. 

Law Enforcement Use Cases for Fog Reveal

✅ Serial cases — multiple crimes with the same m/o

✅ Gang investigations — find local hangouts and track gang movement

✅ Counter-intelligence — tracking potential terrorists and spies

✅ High-profile investigations — sensitive cases involving high-profile suspectss

✅ Drug investigations & cartels — discover local dens and production facilities

✅ Missing & endangered children — track potential suspects without alerting them

✅ Human trafficking — locate trafficking victims and pinpoint handoff locations

Is Fog Reveal Unconstitutional?

Fog Data Science and law enforcement agencies don’t seem to think so, but privacy advocates claim it stomps on our 4th Amendment rights — especially the part about unlawful search

Fog Reveal claims “no suspects or witnesses”, but that’s hardly the case as it allows law enforcement agencies to:

  1. Pick out both suspects and potential witnesses where none exist, allowing them to open cases that otherwise have no leads. 
  2. Track anyone they want without leaving a trail, with no real evidence other than location information, and minus a search warrant!

Given this information, the tagline “everyone is a suspect or witness” is probably more appropriate.

The software also claims to use no Personally Identifiable Information (PII) to obtain device signals… just info users willingly allow apps to collect. 

Then again, do you really go through all those permissions every time you install an app? You don’t for a moment think your app data could wind up implicating you as a suspect or witness in a crime. If you’re like the rest of us, you just say ‘yes’ to get on with your life. 

Fog Reveal doesn’t rely on traditional PII like your Social Security Number, but obtaining data on where you go during the day, and where you sleep at night is pretty personal. There’s no time limit either — law enforcement can track a device signal for as long as it takes to rule out a suspect, and go back in time as far as they like. Under most circumstances, that classifies as stalking, which is illegal in all 50 US States. 

The positives of using powerful software like this are clear, but so are the negatives. Policymakers must be vigilant and clear about how and when law enforcement can use this type of privacy-invasive software.

Mass Data Collection is the Heart of the Matter

Fog and local law enforcement’s disregard for the 4th Amendment raises red flags, but none of this is possible without the intrusive apps and websites constantly collecting your device ID and online activity, or the data brokers that compile and sell it for a profit. 

Data harvesting and sale is an endless cycle.

The diagram above shows the endless cycle of mobile data collection, but you don’t have to participate. Here are a few ways to reduce the amount of data you put on display.

Use What Your Mobile Device Gave You

You don’t have to end up pegged at the scene if you don’t want to. Both Apple and Android give you options to prevent apps from using your AID. On iOS, your AID is called Identifiers for Advertisers (IDFA) and for Android it’s Android Advertiser ID (AAID). 

iOS now requires all apps to ask for permission to access your IDFA, so you choose who has access on an app-by-app basis. You can also shut off IDFA for iOS. To increase privacy, Android goes the extra mile and lets you delete your AAID.

How to Disable or Delete Your Mobile Devices AID

  • iOS: Open Settings > Click Privacy > Choose Apple Advertising > Click Personalized Ads > Turn it Off
  • Android: Open Settings > Click Privacy > Choose Ads > Click on Delete advertising ID > Click Delete advertising ID in the next window to confirm

  • Pay Attention to Permissions Requests

    It’s a chore to scroll through app permissions before installing an app, but it’s important if you want to maintain digital privacy. In 2022, Comparitech discovered that at least one app on every Android device requests unnecessary permissions

    Use your best judgment, and opt out of any permissions that seem unnecessary. Accepting shady permissions requests puts your data at risk of surveillance and potentially allows cybercriminals to access your device. Below are some examples of unusual requests that should set alarm bells ringing..

    • A photo app that requests access to biometric software
    • A game that requests access to your camera
    • An RPG that asks for permission to make or receive calls

    Never be afraid to remove an app’s permissions, it’s completely reversible. Even if you deny a permission request and it affects the app’s functionality, you can enable it in your mobile device settings later. 

    How to Enable & Disable Permissions for Apps on iOS & Android

  • iOS: Open Settings > Select Privacy > Select a permission > Choose an app > Click the button to the right to enable or disable permissions
  • Android: Open Settings > Select Privacy > Click on Permission Manager > Select a permission > Select the app you wish to change permissions for > Click Allow or Don’t Allow

  • Get A VPN And Stay Safe Online

    We value honesty at PIA, so it’s important to know that a VPN alone won’t protect you against the type of surveillance Fog Reveal does. Fog’s service uses AID information that’s already been gathered by an app. You need to shut off your AID before a VPN is going to be useful.

    PIA has advanced tools that protect you, so intrusive software like trackers and malware can’t use your mobile device to spy on you. Our advanced Kill Switch prevents location exposure, even if your VPN is off. We also offer PIA MACE, an all-in-one tool that blocks malware, ads, and trackers before they reach your device.

    Protect Yourself from Unlawful Surveillance

    Unfortunately, we live in a time where playing a seemingly innocent, location-based mobile game could land your device data and online activity in a criminal database. 

    Until web-based surveillance software like Fog Reveal is better regulated, your online privacy and 4th Amendment rights are never guaranteed. 

    It’s more important than ever to remain vigilant about your data privacy and take steps to secure your mobile device. Pay attention to permissions requests and use a VPN. These two small things alone will make a world of difference in protecting you against unlawful surveillance.


    What is Fog Reveal?

    Fog Reveal is web-based surveillance software created by Fog Data Science LLC and used by local law enforcement agencies in the US to track mobile signals

    The software allows users to find potential suspects and witnesses, based on available signals in the area when a crime occurred. The tool is extremely useful for law enforcement, but it’s a step back for digital privacy advocates.

    Can anyone use Fog Reveal?

    No. Currently, Fog Reveal is only available to law enforcement agencies. The software is available for under $10,000 USD a year and it saves valuable time and resources for state and federal law enforcement. 

    Fog Reveal uses mobile signals to track criminals, but innocent, private citizens can get caught in the same net. Don’t let your device get thrown into the mix — protect it against trackers and hide your true location with PIA.

    Does Fog Reveal violate the 4th Amendment?

    Yes. The absence of a search warrant violates US citizens’ 4th Amendment right protections against unlawful search. Despite this, law enforcement agencies and Fog Data Science feel otherwise, so it’s important to protect your mobile devices.

    One subscription to PIA VPN lets you cover an unlimited number of devices, and you get advanced protection against trackers and harmful software. We have a dedicated iOS VPN and Android VPN, and you also get a 30-day money-back guarantee.

    Can a VPN protect you from Fog Reveal?

    Not alone. Fog Reveal doesn’t use the data a VPN protects, it uses your AID, so you need to turn off or delete AID to be fully protected. 

    That doesn’t mean a VPN won’t help at all, especially if Fog Reveal expands its collection methods beyond AID information to other data apps collect.

    PIA VPN prevents apps from tracking your true IP address and device data. We offer antivirus protection in addition to the PIA MACE ad and tracker blocker, and an advanced Kill Switch, to prevent malware from getting in and location data from leaking out.

    Comments are closed.


    1. badnishant79

      Your entire argument hinges upon the police being a safe reasonable and appropriate body to handle the cameras and not the aggressors not the lawbreakers not be abusers. How is that even close to a acceptable premise?

      2 years ago
      1. PIA Team

        Hi Badnishant,
        I appreciate your response and understand your concerns, but we made no such assumptions as you indicated. We’re actually aiming to make people aware of this software and how it invades privacy, as well as advocate for better control over who can use it and when.
        It’s important to make sure that law enforcement respects our constitutional right to freedom from unlawful surveillance, but until things change we can at least educate people on the dangers of these new invasive technologies.

        2 years ago