Data harvesting: What it is and how to stay safe

Data harvesting is the process of collecting information about users, devices, and businesses—and not always with consent. Companies gather data through apps, websites, or third-party tools to learn more about your habits and preferences. The more they have, the easier it is to predict what you’ll do next.

In this guide, you’ll learn how data harvesting works, how it differs from data mining, and what ethical and legal issues come with it. You’ll also see how it can affect businesses, how to limit what’s collected, and whether a VPN can help protect your information.

What is data harvesting?

Data harvesting means collecting large amounts of personal info from users, usually without them realizing how much they’re sharing. This can be done through websites, apps, trackers, or even public databases, all of which gather details about your habits, preferences, and identity.

Some data you give out directly, like when you fill out a form or make an account. But much of it is collected in the background, such as your IP address, clicks, or the time you spend on a page. Companies then use this to profile you, target you with ads, or sell insights to third parties.

Of course, data harvesting isn’t limited to people. It can include details about your device, such as its model, operating system, installed apps, and so on. Similarly, companies can collect information about your business, such as traffic patterns and customer behavior. This helps them adjust their pricing and marketing strategy, or even develop competing services.

How do companies harvest data?

Companies rely on automated tools to gather huge amounts of information from across the web. Two common methods are data scraping and web crawling, typically used together to find and collect everything from user info to business insights.

Data scraping

Data scraping involves pulling info from websites, including names, reviews, prices, or contact details. It’s done with scripts that scan pages and copy the data into a usable format, usually without asking permission from the site or the people listed there.

Scraping tools can grab user info fast and in bulk. Businesses use them to gather leads, study competitors, or train AI systems. Now, some sites protect against this, but many don’t, or can’t. That makes it harder for you to know where your info ends up or how it might be used later, especially if it’s mixed with other data sources.

Some sites try to manage this by offering limited access through official APIs or downloadable datasets meant for ethical web scraping. Of course, that doesn’t stop others from scraping whatever they can reach.

Web crawling

Web crawling is what search engines do to map the internet. They use bots called crawlers that move from link to link, indexing pages and content along the way. Companies may also pair crawlers with data scraping tools to gather huge sets of data.

Crawling isn’t inherently invasive, but it becomes a concern when paired with scrapers to pull user data like public posts, account details, or personal info. Unsurprisingly, this often happens without the user ever knowing.

How do apps harvest data?

Apps harvest data by asking for permissions, tracking your activity, connecting to third-party tools, or logging what you type or click. Some may ask for access to things they don’t need to function, like your microphone or GPS data. Once they have said data, the provider can sell it, use it for targeted advertising, or share it with third parties.

Further reading:

• How to secure your Android app permissions
• How to secure your iOS app permissions

What is the difference between data mining and data harvesting?

Data harvesting is about collecting raw information. Names, locations, device details, click data, the works. It focuses on grabbing as much data as possible, whether it’s through forms, trackers, or scraping tools. Think of it as gathering, not analyzing.

Data mining is the process that comes after. Once the data is collected, mining is how you sort through it to find patterns or insights. This can help reveal user behavior, buying trends, and preferences that wouldn’t be obvious at first glance.

Essentially, harvesting is getting the data, while mining is figuring out what it can tell you.

Some companies (such as social media giants and advertising and analytics firms) handle both steps themselves. They gather user data through their own platforms, then run it through internal systems to study habits, test ideas, or adjust how their services work.

Meanwhile, others buy datasets directly from data brokers, skipping the collection step entirely. These buyers—whether it’s advertisers, political groups, or researchers—use the info to fine-tune campaigns, test different strategies, or predict how certain groups might respond.

The ethics of data harvesting

Plenty of companies collect user data, but not all of them do so in ways that are transparent and respect your rights. These points show where the ethics fly out the window:

• Lack of consent: Your data can be gathered without clear permission, leaving you unsure who has it or what they’re doing with it.
• Hidden influence: Collected info can change what you see online, shaping ads, news and social feeds, and political content without you noticing.
• Discrimination: Sold profiles can influence how you’re scored or assessed in areas like finance, employment, or coverage.
• Unfair profit: Third parties earn money from your info while giving you nothing in return, not even the option to opt out.

Is data harvesting legal?

The legality of data harvesting varies around the world. Our team has analyzed the data privacy laws of 47 countries, looking at everything from biometrics to data sharing and retention. While only five of them have adequate overall protections, many still have specific laws that control how certain types of data can be collected, stored, or used.

Below, you’ll find an overview of our findings in several regions.

Data privacy laws in the US

In our guide to the federal and state data privacy laws in the US, we go over the regulations that control how organizations gather, handle, and share personal information.

Here’s a quick rundown of currently available protections:

• Privacy Act: Limits how US federal agencies collect and share your personal data. You can ask to see, fix, or obtain a copy of any info they store about you.
• Health Insurance Portability and Accountability Act (HIPAA) Act: Stops healthcare providers and insurers from freely sharing your medical data, while also requiring them to have safeguards against data harvesting and usage for non-medical reasons.
• Gramm–Leach–Bliley Act (GLBA): Requires financial companies to tell you what data they collect, how they use it, and lets you opt out of some sharing.
• Children’s Online Privacy Protection Act (COPPA): Protects kids under 13 by requiring websites and apps to get parental consent before collecting or sharing personal info from minors.
• Fair and Accurate Credit Transactions Act (FACTA): Aims to reduce identity theft by requiring businesses to safely dispose of sensitive consumer data and alert users to possible misuse.
• California Consumer Privacy Act (CCPA) and Delete Act: Lets you see, delete, or stop the sale of your personal data. The Delete Act adds more tools for removing your info from data brokers.
• Vermont Data Broker Act: Requires data brokers to register with the state and report what kind of data they collect and sell. It’s meant to bring more oversight to behind-the-scenes data gathering.
• Other examples: Oregon, Virginia, and Colorado have their own privacy rules that let residents view, fix, delete, or opt out of some data usage. New York, Maryland, Massachusetts, and Hawaii are pushing for similar protections.

Related: Which states best protect online privacy?

Data privacy laws in the EU

If you’re in the EU, the General Data Protection Regulation (GDPR) is the main law protecting your data. It gives you the right to see what companies collect, ask them to delete it, and opt out of certain uses. Companies also have to be clear about what they’re doing with your info, or risk fines of up to €20 million or 4% of their global revenue for the previous fiscal year.

Even if a company isn’t based in the EU, it still has to follow GDPR rules when collecting data from people who live there. That means a business in the US or Asia must meet strict EU privacy standards, even if its home country has weaker privacy laws.

On top of the GDPR, many EU countries have their own protections against data harvesting and sharing. Some of these are built into their constitutions or long-standing national laws. So, depending on where you are, you might have extra rights when it comes to how your data is handled.

Global data privacy laws

Many countries outside the US and EU have passed their own data privacy laws, sometimes following the GDPR model. Here’s a quick look at how different places protect you from data harvesting:

• Australia’s Privacy Act 1988: Controls how large companies and government bodies gather and handle your data. It also requires them to tell you about any breaches that affect your personal info.
• Brazil’s Data Protection Law (LGPD): Limits how your data can be collected or used, and gives you the right to view, correct, or remove it entirely. Much like the GDPR, it also applies to international companies working with Brazilian user data.
• Japan’s Act on the Protection of Personal Information (APPI): Protects user data by forcing companies to get consent, be clear about how they use it, and stop sharing info without a valid reason. The EU has approved Japan’s privacy standards, making cross‑border data transfers between the two regions easier.
• South Korea’s Personal Information Protection Act (PIPA): Places limits on how much companies can gather, and requires fast disclosure of data breaches when they happen. As always, you can access, delete, or correct any collected data.
• South Africa’s Protection of Personal Information Act (POPIA): Makes it illegal to collect or share personal info without a lawful reason or consent. It also forces organizations to report data leaks to both regulators and the people affected.

Can data harvesting affect your business?

Collecting data can help you better understand your audience, improve what you offer, and make your marketing more relevant. But when done carelessly or too aggressively, it can backfire and hurt your reputation, bottom line, or even get you in legal trouble.

Users become wary of your brand

If you collect more data than needed or don’t explain how it’s used, people start to lose trust. Over time, they might stop using your service, leave bad reviews, or warn others away. Even if you’re not doing anything shady, vague policies can still push users away.

Trust takes time to earn but vanishes fast when people feel misled. Being upfront about what you collect and why helps, but pushing too far (even once) can leave a lasting dent in your reputation. And that’s not always easy to recover from.

Compliance violations

Data privacy laws set clear expectations for how personal info should be handled. If you gather or store personal info without meeting the legal requirements, you can face fines, audits, or even legal action, especially in places with strict rules like the EU or California.

Even small mistakes, like forgetting to update a privacy notice or mishandling consent, can count as violations. On the plus side, following the rules shows users that their rights matter to you, which helps build trust long-term.

Budget strain

The more data you gather, the more you have to secure, organize, and manage. That means hiring extra staff, paying for training and storage, and investing in systems to keep everything in check. These costs can stack up fast, especially if you don’t plan for them from the start.

Cleaning up messy or outdated data can take time and money, too. If your team’s buried in spreadsheets or digging through data that shouldn’t have been saved in the first place, that’s time and effort better spent elsewhere. Less can often be more in the long run.

Potential data breaches

Holding on to large amounts of personal data makes you a bigger target. If something leaks—whether it’s through a hack, phishing scam, or bad internal practices—you’re the one dealing with the fallout, even if someone else is to blame.

Data breaches don’t just cost money. They also force you to contact affected users, patch up vulnerable systems, and rebuild lost trust. The more sensitive the info, the bigger the impact. Keeping only what you need helps lower the damage if something does go wrong.

Inaccurate metrics

When data is collected without proper context (or is incomplete to begin with), it can give you a false image of how your business is really doing. You may end up chasing trends that don’t exist or changing strategies that were already working, all because the numbers told the wrong story.

It also makes it harder to spot real problems. If the info you’re looking at doesn’t reflect what users actually do or want, small issues can snowball without warning. Instead of fixing what matters, you risk spending time and money in the wrong places.

How to prevent companies from harvesting your data

Short of going completely off the grid, some level of data harvesting is to be expected. Still, you can minimize how much data companies collect about you with these helpful habits:

• Only share what’s needed: Skip optional fields and don’t give more info than necessary when signing up or filling out forms. The less you hand over, the less they can store, track, or sell later.
• Tweak your privacy options: Go into your app, social media, and site settings to turn off location tracking, ad personalization, and background data collection. These defaults usually favor the company, not you.
• Delete browser cache and cookies: Clear them regularly to wipe stored logins, trackers, and behavior data. It helps break the trail that companies use to follow your activity across websites.
• Browse in incognito mode: This stops your browser from saving history, cookies, or form entries. It’s not perfect, but it helps reduce how much gets stored on your device in the first place.
• Install an ad- and tracking-blocker: Besides making the internet less of a chore to browse, some of the best ad-blockers stop third-party scripts from loading, cutting off trackers before they collect your clicks, scrolling data, or time spent on pages.
• Use identity monitoring tools: Whether it’s Norton LifeLock, NordVPN Threat Protection Pro, Surfshark Alert, or others, these tools help you find out if your personal info ends up in leaks or on the dark web.
• Remove your info from data broker sites: Use data removal services like Incogni or DeleteMe to send opt-out requests and scrub your details from public databases.

Can a VPN prevent data harvesting?

VPNs can make it more difficult for online platforms to profile you based on your location by simply masking your IP address. They also help by encrypting your traffic and even blocking ads and trackers in some cases, making it harder for sites, ISPs, and other third parties to see what you’re doing or collect behavioral data.

Naturally, VPNs can’t handle the whole job on their own. They don’t stop apps from overcollecting, sites from asking for unnecessary info, or companies from collecting info you share willingly.

But, as long as you follow smart habits like clearing your cookies, blocking trackers, and limiting what you give out, a VPN becomes a solid tool for keeping your data more private.

Data harvesting FAQs