Stop sharing my contacts with others without my permission
Please immediately disable automatically sharing contact lists for the "People You May Know" feature, and create an explicit opt-in setting. Due to contact list asymmetry, accounts with few contacts can identify which other addresses their 1st degree contacts have in their contact list, without the 1st degree contact expressly sharing that information. This can have adverse effects in terms of unintended disclosure in private life and business contexts.
I just recently invited a friend to Skype who didn't have any contacts. This user could see almost my entire contact list. This is a serious privacy intrusion! If Microsoft doesn't fix this bug immediately, we should perhaps report it as a GDPR violation.