@dansup you can do this is in a privacy-preserving way, no?
- Instead of asking the user to upload their contacts, get the user own email/phone/pixelfed account handle.
- Upload a hash of the private contact information, paired with clean text pixelfed account info.
- Other people now are able to find each other by simply asking your service "do you know anyone with this hash?", and in case your service answers yes, then your app can say "yes, you should talk with so-and-so@pixelfed.