Are their any Privacy implications of intercom ?

Once intercom system based on EPABX/PBX is installed, extensions are reached by private numbers which mean nothing to the outside world. The system does not *ask or *expose your email ID, mobile no, landline number or another personal information for any form of communication. If security staff, resident  or other worker leak your intercom number to 3rd  party, they cannot use it for anything such as unsolicited advertising, tele-marketing, etc. This may be a very significant advantage over any solution which requires security to directly dial numbers using cellular phone (mobile P2P), Mobile CUG or App based Calling solution, where all numbers of all flat owners are loaded to tablets or mobiles given to security, residents, maintenance and facilities staff and the points of leakage are just too many to effectively secure.

Also the system can bar all incoming traffic or traffic from specific numbers if required, just in case incoming call facility or Direct Inward Dialing (DID) is required to be used and is being used for making unsolicited calls by telemarketers.