Isn't there anywhere an option to disable this behavior?
Even gmail doesn't activate your status (when you are idle) as soon as you just click on gmail tab!
It's a very bad behavior that trello shows everyone that you are online even when just you want to view the page!
Wish there was a solution for this terrible behavior of Trello.
Best Answer
I really don't see the issue here. If you open the tab, it should be assumed that you are active on it, even if it was for a second. If you don't want people to know you are on then don't open the tab yet.