What is Actually Possible (And What Isn’t)
A recent viral Reddit thread has brought renewed attention to an often-overlooked issue: how easy it is to extract personal information starting from nothing but a phone number.
Adding to the discussion, an open-source project published on GitHub demonstrates practically how certain information can be inferred without ever directly compromising the target’s device.
Let’s clear things up, without alarmism or clickbait narratives.
The Core Issue: Phone Numbers as Digital Identifiers
Today, a phone number is no longer just for making calls or sending SMS. It has evolved into a true digital identity key, used as:
- a registration credential for apps and services
- a login or account recovery method
- a link between social profiles
- an identifier for messaging platforms
- a reference point for advertisers and data brokers
Unlike email addresses and usernames, a phone number is persistent: people rarely change it, it remains linked to the individual for years, and it is frequently mandated as a minimum requirement.
It is precisely this persistence that makes it valuable—and potentially risky.
This Isn’t Direct Spying—It’s Data Correlation
A fundamental clarification is necessary.
In most cases, there is no direct access to the phone, no message interception, and no real-time GPS tracking.
The mechanism is far more subtle: data correlation and inference.
Starting from a phone number, it is possible to:
- link it to online services where it has been used
- cross-reference it with databases leaked in data breaches
- associate it with public or semi-public social profiles
- deduce interests, habits, and geographic context
- reconstruct activity patterns over time
All of this without “hacking” anything.
What Can Realistically Be Discovered (And What Can’t)
It is crucial to distinguish between actual possibilities and myths.
Plausible Information:
✔️ Approximate geographic area
✔️ Presence on specific social networks or services
✔️ Digital habits (active hours, usage frequency)
✔️ Commercial or behavioral interests
Things That Do NOT Happen:
❌ Access to messages
❌ Continuous GPS tracking
❌ Remote device control
The risk isn’t “control”—it’s invisible profiling.
The Technical Proof-of-Concept: Device Activity Tracker
Making this discussion particularly compelling is an open-source project published on GitHub:
Device Activity Tracker (gommzystudio).
The project does not break WhatsApp or Signal encryption and does not read messages.
However, it demonstrates how it is possible to infer the activity status of a device using nothing but a phone number.
How It Works (In a Nutshell)
- it uses WhatsApp Web as a client
- it analyzes the response time (RTT) of delivery receipts
- it does not send visible messages to the target user
- it does not trigger notifications on the monitored phone
From the response timing alone, the system can deduce whether the device associated with a number is:
- active
- on standby
- offline
This is a concrete example of how metadata—even without content—can reveal sensitive information.
Why This Matters
This project proves a crucial point:
- content security is insufficient if metadata remains observable
- even end-to-end encrypted systems can leak indirect information
- a phone number exposes much more than people realize
The repository clarifies that this is research for educational purposes, but the takeaway is clear:
the problem isn’t the hacker; it’s the data exposure model.
Why This Affects Everyone (Even Those With “Nothing to Hide”)
Privacy isn’t about hiding things.
It’s about who holds power over your data and what they can deduce from it.
Knowing:
- when you are active
- when you are offline
- how predictable you are
- which services you are connected to
is already sensitive information.
Today, a phone number is a weak digital identity because it is:
- unique
- hard to change
- required everywhere
Practical Steps You Can Take
Without resorting to extremes, a few best practices genuinely help:
- avoid using your phone number as the primary login method when unnecessary
- limit contact access granted to apps
- use separate numbers for critical services versus “throwaway” accounts
- review privacy settings on social media and messaging apps
- be wary of services that ask for your number “just for convenience”
It’s not about paranoia; it’s about digital awareness.
Conclusion
This isn’t science fiction.
It isn’t Hollywood hacking.
It is the result of years of data accumulation and correlation.
The real question isn’t:
“Can they track me?”
But rather:
“How much information am I leaking without realizing it?”
Understanding how this works is the first step toward regaining control of your digital identity.
