> many popular cycle tracking apps have a bad rep of sharing data eagerly with Facebook and other entities
Many no longer have a choice as to whether to turn their data over to law enforcement who may use it to deny lifesaving medical care. (Florida briefly tried to make reporting periods mandatory for student athletes, too, but that fortunately failed)
In my opinion if you're running something like this in a location where you might be forced to share the data for such malicious purposes with law enforcement then it should be your responsibility to (re-)design the app to provide users with a local-only option for data such that there's then nothing personal on the servers to be requested by law enforcement.
> Florida briefly tried to make reporting periods mandatory for student athletes, too, but that fortunately failed
Your wording is false. Florida is a state and the state never did this. The reporting is already on the form, but is optional. Some private industries wanted to make it mandatory, but the gov has no control over this.
Many no longer have a choice as to whether to turn their data over to law enforcement who may use it to deny lifesaving medical care. (Florida briefly tried to make reporting periods mandatory for student athletes, too, but that fortunately failed)