This is more of a general announcement, I guess, but today I happened to run a reputation recalc on my account (which one can do by going here), and I noticed that I lost 104 points. This is an unusual number (i.e. it's not a multiple of 5) and it's rather large, so I was a bit confused as to the possible reason. But after thinking and looking around for a bit, I noticed that a rather active user has deleted their account, and that the disappearence of their upvotes from the system is now starting to take effect. This has happened before; see this thread. So if you lost reputation recently (or notice a loss in the near future), this may be why; there is no automatic explanation, or even notification, of when a global reputation recalc is performed in the SO system, so I wanted to bring this up preemptively. This aspect of the reputation system is discussed here on meta.SO.
I've been advised to avoid mentioning who left in this thread. If you don't know, then I suppose it doesn't matter too much; a quick glance at the user list should be enough for most of our active users to see who is missing.