Spotted this in the guardian link: >> “When we looked into the steps people were going through to verify their accounts we found that in some cases people’s em

Spotted this in the guardian link: >> “When we looked into the steps people were going through to verify their accounts we found that in some cases people’s email contacts were also unintentionally uploaded to Facebook when they created their account,” Im struggling with the "unintentionally" part and to play devils advocate trying to figure out if it could be possible. Perhaps they had a service already that performed the login to upload peoples contacts on request and to save time reused this service to also verify the account?