ddrescue doesn’t work properly on audio discs (even if you use the correct sector size of 2048 bytes). Have you tried something like cdparanoia https://www.xiph.org/paranoia/?

YouTube blocks it. There are extensions to allow it (like Vinegar) but by default it’s blocked. Brave might work around YouTube’s block in the same way.

Without looking at it it’s probably making a unique request to a resource on a NextDNS subdomain and watching where the request comes from. Like pulling an image from (unique _string).check.nextdns.com. This requires nothing special on the client, it’s making a standard request, and as part of that it needs to do a DNS lookup.

If the source of the and your IP are similar then it’s likely the same network, otherwise it can correlate the source with known resolvers.