Objects cat be triggered to react to loud trigger words from a distance.
these words currently are:
tick, wakes, sleeps , whistle, whistle, calls and modify.
So when someone logs in, being a loud message, any object can react to it.
The reason for this limitation on loud command is we dont want someone shouting or doing a command loudly that they triggers an action in a room with no one in it.
For example if an object reacts to 'talk' and someone far away talk to the receptionist loudly from the open field, she wont react. but if your standing right next to her, she will.
Thee ractions wont happen if the object is switched off
However there are some trigger words that ignore an objects swicth satus:
arrives,leaves,shout,switch and modify
So you can switch off an object, and have it turn back on when somone arrives.