Or turn on full privacy mode and only approve followers you know.
Removing privacy zone should be really easy with basic math/geometry. I was gonna build a proof-of-concept app to do that, but it probably would be actually used for evil (instead of just serving as a PSA that privacy zones may not be that private). As others have noted you can find addresses from real estate records too (assuming people use real names in Strava; most do).
This is particularly worrisome for Freezing Saddles since every mile counting encourages folks to start recording at home. Can BAFS get data on “private” rides? Looks like it should be able to if it requested “view_private” scope. I won’t be offended if you tell me to RTF code, and hope you aren’t offended that I haven’t investigated further. I could rationalize that you might’ve trashed the production code but truth is I’m lazy.