If you don't provide a real name when registering a domain, you lose the domain as soon as the registrar gets served with papers. This is an ICANN policy, you can't escape it.

All the registrars sell access to the real names behind their "privacy protection" service. They do not bother checking if the requester has a warrant or is even affiliated with law enforcement. They simply charge a fee (around $50 per request) to prevent bulk extraction, and possibly review the top 50-100 highest-volume requesters.

njalla is really the only way around this, but you have to trust them with legal ownership of your domain.