Is there a way to know who has asked to be alerted when your Profile is updated? I made a brief change to mine yesterday while testing a problem. If not for the fact that I received a bounceback notice today, I would not have known this person is "monitoring" my updates.

No. This has come up several times in the past, and I'm sure those old threads are still out there where people weighed in on this, but the overwhelming concensus on this was to not give members a list of the members who have subscribed to their Profile. Rationale being that if you know the member you're subscribing to will know you've subscribed, it will make some people less likely to subscribe. E.G. Let's say you want to subscribe to the Profile of that boy you had a crush on in high school who never knew about it....maybe you're just curious about what he's doing in his life today and want to keep up with him. But to him it would be a little strange for you to be subscrbing to him. If you know that he's going to know you're "watching him", you decide not to subscribe at all because you would feel uncomfortable having him know. There's such a thing as too much information, thus it was decided to keep people's own Profile subscriptions private.