It doesn't take much imagination to come up with a hypothetical scenario. Person is writing to their partner but receiving no reply, however they can see that their partner has been online for the past 30 minutes. Person is convinced that their partner is talking to that one guy from the gym.
I have definitely been called out for being online but not replying, so I can easily imagine how that can end up becoming a big drama in some relationships.
Maybe you have a crazy manager. They see you were online when you were meant to be working. They use this to justify their thoughts you’re lazy. Who knows?