Aircraft Registration Database
The FAA maintains a database of all aircraft registrations. It makes this database publicly available, including the names of all owners and their home addresses. As a practical matter, this means that anyone who searches for your name or your plane’s N-number on the internet can easily find your home addresses, your name, the names of any co-owners, and all the planes you own.
If you want to hide this information, there are two things you can do.
List a PO box as a mailing address. You still need to provide a residential address in case the FAA needs to find you, but they won’t publish the residential address in the public database. People can still find your name and the planes you own, but they won’t be able to find your home address. Also, many services and individuals keep historical copies of the aircraft registration database. This means that if you list your home address as the mailing list on the aircraft registration and change it later, people will still be able to find your home address in old copies of the registration database.
Work with an attorney to establish a shell corporation. This will hide your plane’s owner from public view. Note that in some states many corporate records are publicly accessible, so unless your attorney is careful it will still be possible for a mildly motivated individual to guess who owns a particular plane by examining corporate records.
Flight Tracking Services
A variety of services (most notably FlightAware) combine real-time FAA feeds with networked ADS-B receivers to provide live tracking for all IFR and limited VFR traffic in the US. These services usually also archive the data, allowing users who pay a fee to view all the flights a particular plane has flown. This means that if your fly IFR, anyone can look up your plane on these services and see where it’s gone. If it unsettles you that anyone can Google your name and see your plane’s location, add your plane to the FAA’s blocking list. The information is on the FAA’s BARR page. In brief, you send an email to ASDIBlock@faa.gov with your name, N-number, and your contact information. After some back-and-forth to verify your identity, the FAA will add your aircraft to the block list. This will prevent your aircraft from showing up on any flight tracking services like FlightAware. If you still want to be able to use FlightAware for your own purposes, FlightAware can give you private access in exchange for a fee as explained on their commercial offerings page.