Hello Mr. Cloudflare, Your whole understanding of how XMR works seems to be wrong; theres no concept of spend outputs at all, to deanonymize tx with a certain certainity one would have to own around 83% of the networks outputs.

Theres a good academic read about this here: https://lab.getmonero.org/pubs/MRL-0001.pdf and here: https://lab.getmonero.org/pubs/MRL-0004.pdf

And also a privacy improvement which gets into effect in about 25 hours or so with the next hardfork called RingCT, which has been peer reviewed by Ledger journal: http://www.ledgerjournal.org/ojs/index.php/ledger/article/do...

Optional privacy a la ZCASH is broken by design and cannot work, you are still able to have tainted coins and do blacklisting etc, its effectily useless, also it opens up a whole world of other attack vectors like this one: https://github.com/zcash/zcash/issues/1360#issuecomment-2461...

A good read for everyone unbiased tho a bit old is here (which explains the inner workings): https://lab.getmonero.org/pubs/MRL-0003.pdf