>>2077704>spywareAll extraflags sends to the developer's servers are the post number and your set flags. Your IP is needed to pass the messages as with literally everything you do over the internet.
Meanwhile you're loading javascript from Google-analytics to visit this page which is served by cloudflare and so on and on. You're probably using Chrome, a browser that now exposes your USB devices directly to websites. And you're on Windows and you know full well what that means in terms of privacy.
If you install extraflags, it'll be the least spyware software you use to browse 4chan.