I built something similar as a node module a while ago : https://github.com/thibauts/node-host-filtering-proxy

Is it possible to have an admin user v/s normal user where normal users simply get blocked/unblocked without the "page control" or any ability to blocked/unblock, etc.

Not yet, but that feature has occurred to me. Since it looks like there's some interest, I may do another round of feature development.

It's an alternative approach to a browser plugin to block ads and other stuff.

Is it going to be a replacement of privoxy?

Oh, interesting. I didn't know that existed! Pretty similar idea. Mine's more focused on content blocking than specifically privacy. This should also work cross platform since its all written in go. (I've used it on windows, mac, and linux) If there's enough interest, I could polish this into a more complete product. I've been meaning to do a rewrite done right based on this prototype but need some motivation/reason to improve something that's "good enough" for me personally blocking ads and cruft while reading the news.

Fantastic work! What's the license?

I need to add one (tonight perhaps), but its basically: do what you want, but if it breaks it's not my fault. I'm just flattered if anyone finds it useful.

MIT. Just added the license.

Running

If you have a go workspace set up, simply build and run out of the box

But what if you don't?

Pre-built binaries are now available for mac/win/linux 32/64 bit:

https://github.com/jcuga/proxyblock/releases/tag/v0.1-alpha

You need go to build it (see: https://golang.org/doc/install)

I can add pre-built binaries in the future, especially since go let's you cross compile easily.

Nice work, I'll keep an eye on this project.