This is something that isn't widely known, but a great thing to do for obvious reasons.

If you fly in the system, even VFR using flight following, the entire interweb knows and can track your flights. If you wish, you can request that the FAA keep this info private.

It's free do to and super easy. All you have to do is send an eMail in and the data is blocked.

https://nbaa.org/aircraft-operations/security/asdi/

Good stuff- thanks for posting!

It's worth noting that this only affects FAA broadcast/subscriber use of ADSI information which the FAA sends out from their systems to specific recipients. ADS-B receivers will still see you, and if you have 1090 Mode S you are not anonymous even when squawking 1200 as your hex ID is always sent in the data packet. Also consider that sites like ADS-B Exchange are not bound to ADSI rules since they're community-fed, so you are still not 100% invisible to the world since it's a fair bet one of those ground receivers will see you.

This helps with most of the Internet tracking sites though, and they also seem to adhere to ADSI block requests even when ADS-B is supplementing their data. It will prevent casual identification, but someone who knows what they're doing may still be able to figure it out unless you are operating w/o a transponder (in which case this is all irrelevant), or using 978 UAT with a 1200 code and the transponder set to anon mode.