What’s the attraction for pirates? Firstly, it’s the anonymity (or technically pseudonymity). Transactions rely on public and private encryption keys. Although the transactions are transparently recorded and stored in the ledger, the individual behind them is anonymous. Whether sharing pirated content or exchanging Bitcoins – your real identify is hidden.
Another attraction of blockchain is it’s a distributed ledger. There’s no central server or single entity. For pirate P2P sites, being shut down or blocked is one of the hazards of their trade. With blockchain’s distributed nature this threat is diminished.