Obviously I can't speak for Piratechain, but Loki does have private-by-default transactions. We use ring signatures, stealth addresses, and RingCT to serve private transactions. I am happy to explain any of these concepts if you need, or you can find them in our white paper. A lot of these features have been pulled from Monero, so if you are familiar with that project then a lot of these concepts will be familiar. A key difference is that our ring sizes are fixed (whereas in the past Monero's have been dynamic), which helps to prevent users from getting fingerprinted.

We have also recently enabled checkpointing. Checkpointing further secures the blockchain and helps to protect it from 51% attacks.