When you pass someone on your bike do you let them know before you do so? With a bell or verbally?
If they seem to be reasonably consistent in their path I usually will pass at a safe distance without calling out. If they are wandering a bit, I will slow and announce by voice or bell. If I see that their ears are connected to a device, I don't bother.
Do you expect others to let you know when they are passing?
Not unless they do it in a way that crowds me or have way more speed.
Does it annoy you when you are passed without warning or do you not care?
I am not annoyed by a pass, but I may be annoyed by the manner the passer is riding