Tech Guides

Your data online: what companies collect and what you can do about it

Informatics HubAugust 20267 min read

Every time you use a free app, visit a website, or search for something online, data about you is being collected, stored, and in many cases sold. Most people have a vague sense this is happening but no real picture of what it means in practice. This post makes it concrete.

Understanding what data is collected about you is not just a privacy concern. As a developer or engineer, understanding data collection practices makes you a better builder because it forces you to think about the systems you create from the perspective of the people whose data flows through them.

What gets collected

Behavioral data

Every click, scroll, pause, and tap you make on a website or app is potentially logged. How long you hovered over a product. Which articles you read to the end. What you searched for and what you clicked on in the results. This data builds a detailed model of your interests and intentions.

Location data

Your phone knows where you are at all times. Apps that request location permission can log your movements continuously. Over months this data reveals your home address, your workplace, your daily routine, who you spend time with, and where you shop, eat, and travel.

Device and network data

Your IP address, device type, operating system, browser version, screen resolution, and installed fonts are all collected automatically when you visit most websites. Combined these create a fingerprint that can identify you even without cookies.

Social and relationship data

Platforms that have access to your contacts, messages, or social graph build a picture not just of you but of everyone you are connected to. Even people who have never signed up for a service can have shadow profiles built from data collected by others.

The product is free because you are the product. This is not a clever saying anymore. It is a literal description of the business model that funds most of the internet you use every day.

Most people share far more data than they realize simply by using apps and websites without checking default settings

Practical steps that actually help

🔍

Use a privacy-focused browser

Firefox with uBlock Origin or Brave block most trackers by default. Chrome sends significant data to Google by design.

🔎

Switch your search engine

DuckDuckGo and Brave Search do not build a profile of your searches. Startpage shows Google results without tracking.

📱

Review app permissions

Go through your phone settings and revoke location, microphone, and contact access from apps that have no reason to need them.

📧

Use an alias for signups

Tools like SimpleLogin or Apple's Hide My Email let you create throwaway addresses so your real email is never exposed.

🌐

Enable DNS over HTTPS

Your DNS queries reveal every website you visit to your ISP. DNS over HTTPS encrypts these lookups so your browsing stays private.

🗑️

Delete what you do not use

Every old app and account you no longer use is a liability. Delete unused accounts and revoke access to apps connected to your Google or Apple account.

What this means when you build things

Every piece of user data you collect as a developer is data you are responsible for protecting. The privacy principles that apply to you as a user apply to the people using what you build. Collect the minimum data you genuinely need, store it securely, and be honest with users about what you collect and why. Building with privacy in mind is not just ethical, it is increasingly expected by users and required by law in many regions.

Key takeaways

• Behavioral, location, device, and relationship data are all collected continuously by most apps and websites
• Browser fingerprinting can identify you without cookies using freely available technical information
• Switching browsers, search engines, and reviewing app permissions are the highest impact first steps
• Developers have a responsibility to collect only what they need and protect what they collect