Every field you fill out is a data point. Most of those fields aren’t required — they just feel that way. Here’s how to read a registration form like someone who’s seen where that data ends up.

Every time you register for an online service, you create a data footprint. That information becomes part of a permanent profile — even if you later delete the account, the data may persist or have already been sold. The data harvesters don’t need you to stay subscribed. They needed you to sign up.


Registration Field Guide

Field What It’s Used For Recommendation
Name Account identification, personalization, fraud prevention Use first name only if possible; use a pseudonym for low-stakes services
Email address Login, account recovery, marketing Use a secondary or alias email; avoid your primary email
Birthday Age verification, “personalized” experience, advertising Provide only if legally required; shift the date by a few days for protection
Gender Demographic targeting, advertising Optional in most cases; skip or select “prefer not to say”
Location / Address Shipping (if needed), localization, advertising Provide only if required for service delivery
Phone number 2FA, account recovery, marketing Provide only if required; use a Google Voice number or secondary number
Username Public-facing identity Do not use your real name or any username tied to other accounts
Employment / Company Professional networking, advertising Leave blank unless the service genuinely requires it

Minimum Necessary Information

Only provide information that is required for the service to function. Ask yourself:

Most “required” fields in registration forms collect data for marketing purposes, not functional necessity. A red asterisk doesn’t mean they actually need it — it means they want it.


Registration Across Common Platforms

Platform Real Name Real Email Real Birthday Real Phone
Banking / Financial Yes (required) Yes (required) Yes (required) Yes (required)
Social Media Pseudonym preferred Secondary email Optional / shifted 2FA only
Gaming / Entertainment Pseudonym Secondary email Optional No
Shopping Ship-to name Yes (order receipts) No No
News / Content Pseudonym Secondary email No No
Health / Medical Yes (required) Yes (required) Yes (required) Yes (required)

Linking Accounts (Sign In With…)

“Sign in with Google” / “Sign in with Facebook” / “Sign in with Apple” — convenient, yes. But convenience is what the data harvesters are selling you.

Sign in with Google / Facebook:

⚠ WARNING: Using “Sign in with Facebook” across multiple services means a single Facebook account breach cascades to everything you’ve linked. One domino. Every account.

Sign in with Apple:

Best practice: Create a dedicated account with an alias email for each service. More work upfront. Much less damage when (not if) one of those services gets breached.


Alias Emails

An alias email forwards to your real inbox but hides your actual email address. This is the single most effective registration privacy technique available to regular folks.

If you use Gmail, start using the +tag trick today. It costs nothing and tells you exactly which companies are selling your address.


Set up one alias email service. Use it for every new registration going forward. You’ll have a clean record of every service you’ve signed up for, and when one of them sells your data, you’ll know exactly who did it.