It doesn't. Blocking a website is one of the simplest things an extension can do: you write a list of domains, the browser refuses to load them. Chrome's declarativeNetRequest API does the enforcement natively. No server needs to be involved, and nothing about your browsing needs to leave your machine.
When a blocker asks you to sign up anyway, the account is doing something for the company, not for you. It ties you to their sync service, it gives them a channel for upgrade emails, and it turns a local browser setting into a relationship with a subscription attached. For a tool whose whole job is reducing noise, starting with a signup form is a strange first impression.
Barricade has no account system at all, and no server of its own. You install it, type a domain, and it's blocked. Unlimited sites, free, forever. The blocklist, schedules, stats, and time budgets are all stored in your browser and exportable as a JSON file whenever you like. The only network activity in the entire extension is the Stripe-backed payment library checking whether you bought Pro, a one-time $14.99 that adds schedules, a password lock, and strict mode.
No analytics, no tracking, no email capture, no "log in to continue". The privacy policy is short because there is very little data to have a policy about.
Add Barricade to Chrome, freeAlso see: BlockSite alternative · StayFocusd alternative · privacy