Ask HN: Proxy in the browser (for DIY scraping)

Scraping.com is a website offers scraping of content of target.com

Is it possible that visitors of scraping.com host a (JS?) proxy in their browser. So that scraping.com routes HTTP requests through the users to target.com.

The purpose of this would be that the users' IP show up in target.com' logs instead of the (one) from scraping.com