[mmis1000]

If I am using a chat app, I definitely have no interest to tell you anything outside of the chat window. Why on the earth should I tell everyone that I am in front of the computer or not? Can't they just tell if I use the chat app recently or not? (It's public info anyway, if i am chatting in group, others will see the message.) Such function is definitely a security risk and I don't think I need it.

Even only with public group messages, you can figure out some others sleep schedule or when is he/she mostly active if you have enough data. This api will only make things worse because it trace you 'actively' now.

Besides that, you are able to send message when other is not here is the biggest point of a text chat app. If you must chat instantly, why not just call with phone?