I used to live in an apartment complex that had an electronically controlled front door to the building, coupled with a very annoying call box.
The called party just has to press 9 on their end, front door unlocks.
This method is meant to selectively admit guests to the building.
What happens if you forgot your card key? You’d have to choose your roommate’s name in the list, or hope some stranger would let you in.
What if a robot answered and would let you in, provided the right PIN was entered? Easily done…
In OS X 10.8 I’ve found a few issues where the Calendar application won’t show calendars properly from any other service, including Google and iCloud. My solution was to clear the cache located in “~/Library/Calendars/Calendar Cache”
Do this with the program closed, then go into System Preferences and re-enable your Calendar accounts.