Ads follow you around the internet through technology called 'cookies.'

How companies track you around the internet, explained

Being able to track how users behave on websites is a massive opportunity for companies to hone their products, target their ads, and more. Dozens of trackers are on the average website you visit, depending on how you deal with that site's cookie policy, and Google is the chief tracker of them all. Learn about these companies and what they are tracking with this informative blog visualization.

Social media platforms benefit not just from ensuring they have satisfied users, but also from the personal data they scoop up and can then sell to online advertisers.

Data privacy advocates worry that Google collects too much personal information

Politicians have also criticized whether the search engine exerts too much control over gatekeeping online information and influencing what is considered fact or fiction, deviating from its original corporate motto of "don't be evil."

Your device can become infected with malware by simply browsing the internet

During a drive-by download attack, security flaws in a program or operating system (e.g., Windows) used to access online content are exploited, and malicious code is downloaded—for example, when loading a hacked webpage—onto a user's device without their knowledge. Restricting internet browsing to safe sites and installing security updates helps prevent these attacks.

Technical vulnerabilities prevent full-proof anonymity when browsing the dark web

Despite encrypting data and relaying it within the Tor network, traffic between the network exit and the final destination is no longer hidden and can be captured. Law enforcement agencies can also attempt to deanonymize users by monitoring and matching data signal patterns entering and leaving the network via a correlation algorithm.

A major dopamine hit from social media use comes from unpredictability—not knowing if the content users post or share will get the 'like' from other users, triggering cycles of anticipation similar to those experienced with a slot machine.

Facebook's algorithm chooses content to display on the News Feed based on user data

It employs machine learning to prioritize posts and ads based on user interactions, content type, and post timeliness, creating a personalized, engaging experience for each user.

Web scrapers extract data from a webpage's underlying HTML code and have been used to generate sales leads, collect competitor information, identify counterfeit products, and optimize sites for search engines.

Credit monitoring services may oversell the benefits of dark web monitoring

Currently, technology exists to scrape and download data from webpages, which can then be analyzed to identify a user's information. However, scrapers cannot access or remove personal data from dark websites because they are often protected by paywalls, rendering monitoring ineffective beyond reporting publicly available data breaches.

Cookies were originally used as low-stakes ways to test the temperature of an oven

In 7th century Persia, bakers used small mounds of dough to test the heat in ovens before baking larger cakes. Afterward, they'd add honey, nuts, and other items to the small mounds, creating early cookies.

Targeted ads accounted for 80% of Google's parent company's total revenue in 2020

Ads in Google Search, YouTube, and other products brought in $147B for Alphabet, with ad click costs ranging from $7 to several hundred dollars. YouTube's ad revenue alone jumped 49% year-over-year in one quarter.

As of 2026, age verification systems on online platforms have included the collection of personally identifying information, such as government IDs, and biometric age checks that rely on AI-based facial recognition.

In defense of the advertisement economy

Advertising is frequently reviled for how it clutters up public spaces and our everyday experiences. Nonetheless, it allows for vast amounts of goods and services to be rendered free to millions of users—and gives users the option to pay with money or time and attention.

The average American likely doesn’t notice how many ads they’re targets of per day

The average American is targeted with roughly 5,000 ads each day—but the conscious mind likely isn’t capable of recalling the majority of those. Even still, many consumers have reported ad fatigue due to the near-constant onslaught of ads.

Listen to the history of the first banner ad on the internet, which went live on Oct. 27, 1994, on HotWired.com and pioneered the modern concept of digital advertising.

Trudging through the dark web to expose child abuse

A computer expert who created a system to track down sources of revenge porn and an investigative journalist joined forces to investigate digital abuse. Their investigations focused on so-called clear nets, websites that make up the web most users surf. Then, they turned their investigation toward the dark web, where they found a child abuse website with more than 1 million registered users.

Privacy concerns in the credit scoring system

Because credit scores use a lot of personal information (such as whether or not someone makes credit card payments on time), some worry their privacy is being compromised in the data collection process.

The majority of Meta's revenue comes from advertising

Since introducing Facebook Ads in 2007, ads have become the main way Meta makes money and keeps the social media platforms free for users. Meta's targeted ad program allows businesses to set a maximum advertising budget and be charged only for the actual number of impressions an ad receives. In 2025, $196.175B of Meta's $200.966B annual revenue came from advertising.

Web crawlers and internet archives and back-ups limit perfect erasure of online data

Crawlers are programs that automatically browse the internet for links and index pages for search engines to pull up when page content matches search queries. Networks of global data centers also create copies of content as fail-safes for potential failures to ensure access isn't ever lost.

The dark web can expose anonymous users to potentially dangerous environments

Browsing the dark web requires onion routing, which prevents visitors from being identified and the locations from which they connect from being traced. This has been useful to activists in environments affected by political oppression or instability. However, those unfamiliar with navigating the space may encounter malware and network attacks from denizen hackers.

YouTube's recommendation algorithm relies on over 80 billion daily pieces of information

These signals include which videos a user has watched, searched for, and liked, as well as channel subscriptions and feedback selections, such as videos marked "not interested." Each user's viewing habits are compared with those of other users with similar habits, and this information is used to suggest additional content.

US federal law dictates that all ads must not be deceptive

It also dictates that all ads must be “not misleading, and, when appropriate, backed by scientific evidence.” However, enforcing these laws can be difficult given the massive number of ads that run all over America each day. This explainer on the subject from the FTC provides more information.

Advertising-related activity may have supported roughly one in five American jobs as of 2024

That’s according to a study commissioned by The Advertising Coalition, conducted by S&P Global Market Intelligence, which also found that the advertising industry powered more than 20% of total US economic output at the time.

Third-party apps are not made by the manufacturer of your device or its operating system but are checked for malware and compatibility before being made available in official app stores, like Google Play.

How political campaigns use your data

What do campaigns know about US voters, and how do they use that information to shape their strategies during elections? US political campaigns base their strategies and tactics on data collected from more than 200 million voting-age Americans. This visualization by Reuters breaks down how data firms create national databases of voter files, collecting information from a variety of sources to create detailed voter profiles and how political campaigns use that data.

Social psychologist Jonathan Haidt, author of 'The Anxious Generation,' contends that children are losing the ability to pay attention as they spend half their lives perusing social media content designed to hook them.

Aimed at increasing user engagement, social media algorithms will intentionally show content in feeds that is misaligned with users' beliefs because such content is more likely to be commented on.

Cookie Monster evolved from the Wheel Stealer, a monster obsessed with a wheel-shaped cheese snack.

The dead internet theory suggests that mostly bots are interacting online

The dead internet theory proposes that bots create most online content. These bots are believed to create social media posts to boost engagement and increase advertising revenue. However, the accounts doing the liking and commenting are also believed to be bots. The theory suggests governments use bots to manipulate public opinion.

Why TikTok's algorithm is likely driven by what you linger on

While the inner workings of the engine driving the vast majority of the app's engagement remain a secret, it is understood to rely heavily on what content users spend the most time watching rather than swipe past. Experts believe the app can develop user profiles robust enough for its algorithm to consistently match engaging content to in as little as two hours.

Bias can manifest in algorithmic decisions because the program follows rules that may have been written by individuals unaware of their own biases.

As of 2025, there are no federal laws involving privacy and smart city technologies

Advancements in cloud technology and artificial intelligence allow cities to capture, store, and analyze more information than ever before. Experts warn that the unhindered ability to collect and use this data may infringe on residents' rights and endanger them if the data gets into the hands of malicious parties.

A US Department of Defense research lab developed the technology for the dark web

Although encryption existed to mask the content of communications across the internet before the 1990s, those managing overseas network infrastructure could determine a spy's affiliation based on where they saw data sent to and received from. To keep this information secret, the US Naval Research Laboratory developed onion routing, which enabled anonymized web browsing. The release of the technology to the public obscured sensitive communications further by growing the volume of anonymous data.

Facebook dominated US social ad spend in the first half of 2024

This data visualization shows the social media platforms where advertisers spent the most money in the first six months of 2024, with Facebook leading the pack taking home 36.3% of US social ad spend.

Google Search incorporated AI Overviews in 2024 to fight back competitors

Analysts believe that generative AI tools—not antitrust rulings—are Google's biggest threat because they draw users away from traditional search and potential ad revenue. AI partnerships, like the one between Apple and OpenAI, may further reduce Google's market share.

The first social media platforms date back to the late 1990s, and their algorithms were typically chronological, with entities like MySpace and Facebook feeding users content from the most recent posts to the oldest.

The TikTok ban isn't just for TikTok

The Protecting Americans from Foreign Adversary Controlled Applications Act makes it unlawful for any “foreign-adversary controlled” entity to distribute, maintain, or update any “website, desktop application, mobile application, or augmented or immersive technology application” within the US.

Explore internet usage data, including how humans consume 1.2 billion years of content yearly

About half this time consists of content from social media platforms, where the average user spends about 18.5 hours weekly. An estimated $3.66T was spent on consumer goods by online shoppers in 2025, though nonconsumer goods, such as flights and hotel stays, greatly increase this estimate.

Social media addiction, though not a clinical diagnosis, refers to the idea that infinite scroll, notifications, and algorithms override one's ability to stop using them.

Trademarks are a form of consumer protection

Trademarks help brands distinguish their products from competitors, but they also give consumers clarity around the product they are buying and where it comes from. Distinguishable names help prevent consumer confusion and maintain a consumer's ability to choose their preferred product and brand.

Microchips in payment cards improve security by generating unique transaction codes

Magnetic strips store unchanging data that is easily cloned, but microchips act as miniature computers that encrypt sensitive data. They also resist fraud by creating data unique to each transaction, preventing duplication.

Learn how governments around the world restrict internet access for their citizens

Various countries around the world, including China, Russia, and Iran, control their local DNS infrastructure, allowing them to block access to online content by preventing the internet "phone book" from finding the IP addresses for specific URLs. Government-controlled internet service providers can also cut off access entirely or throttle specific traffic.

Explore metrics on the Tor network, the infrastructure of the dark web

While internet traffic within the network is concealed, public, nonsensitive data can be used to estimate the number of active users, the number of relay servers, network performance speed and reliability, etc. Researchers can use this data to indirectly identify political upheavals or censorship campaigns worldwide, such as the Arab Spring.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

Unlike the models made by large AI companies, open-weight models can have their safeguards removed or weakened, a process that has become increasingly easy and may expose users to harmful information.

While influencers try to make money off of their posts, that's not always the case for content creators.

Distinguishing between Web 1.0, 2.0, and 3, all made possible by the internet

The World Wide Web began as read-only, static webpages on Web 1.0, where data could not be entered. With Web 2.0, the online interface became a read-write space for data entry, post creation, and forum participation, among other activities. Web3 is intended to be decentralized, user-owned, and built on blockchain technology.

Onion routing disguises internet traffic in layers resembling a nesting doll

Data is encrypted at least three times before being sent to a node—a server that can only decrypt one layer. Then, the underlying encrypted data is relayed to another node, and the process repeats until all layers are decrypted. Thousands of possible nodes make it extremely difficult to trace activity within the system.

Apple’s '1984' ad aired once during the game and permanently shaped their advertising

During Super Bowl XVIII, Apple aired its dystopian “1984” commercial once to a mass audience, introducing the Macintosh and positioning Apple as a challenger to IBM’s dominance in personal computing.

How big brands keep your loyalty

We perceive ourselves as rational decision-makers—but research about our consumption habits suggest we are easily played by clever marketing. Here's how big brands design their branding to keep you coming back.