One of the biggest and most overlooked issues with privacy on any cellphone, "open hardware" or otherwise, is the phone part. The baseband processor (BBP) will

One of the biggest and most overlooked issues with privacy on any cellphone, "open hardware" or otherwise, is the phone part. The baseband processor (BBP) will be a proprietary black box until at least one of the carriers decides to allow an open source BBP to access their network and exchange data. Even once that happens, if it ever does, the second your BBP accesses the network you are vulnerable to snooping, tracking, and spoofing like everyone else on the planet. At the end of the day you are relying on a suspect network connection, hosted by a profit seeking corporation, regulated by a privacy hostile government, to maintain your connection to the world. No matter how "free" your device is, the network itself will never truly be free.