> Have there already been cases of websites making their visitors unwitting peers, similar to e.g. JavaScript cryptocurrency mining?
I haven't seen it yet in websites, but I have seen video streaming apps using torrents on the backend without informing users about it. It's caused people who thought they were legally (or at least 'safely') streaming shows and movies for free using something they found in the app store to be surprised when they got hit with DMCA notices from their ISP.
I did a PoC in college (~2008!) where I coded a distributed rainbow table generator in JS. It'd assign a block of hashes which would get sent back to the server. We showed that a single webserver distributing the work in a naive js implementation (long before webworks and wasm) could outpace a fairly decent local c impl (we were undergrads, so definitely not optimization experts).
Was fun until sites actually got on board with salting.
I haven't seen it yet in websites, but I have seen video streaming apps using torrents on the backend without informing users about it. It's caused people who thought they were legally (or at least 'safely') streaming shows and movies for free using something they found in the app store to be surprised when they got hit with DMCA notices from their ISP.