A Zcash user recently made a challenge for anyone to tell where his coins came from that went from taddress->zaddress->zaddress->taddress. The winner only had

A Zcash user recently made a challenge for anyone to tell where his coins came from that went from taddress->zaddress->zaddress->taddress. The winner only had to look at past transactions and find the same coin amount to find the original t-address. That is why privacy-by-default is very important, and why right now Monero should be considered more private.