I think this is a bug, but it's minor and probably of little consequence, so I'm labeling it "#misc" rather than "#bug".
If a moderator goes to Admin - Members, then clicks Filter, and checks off more than one checkbox, sometimes the result is questionable and probably not correct.
If I check both "Not Confirmed" and "Bouncing", I seem to get both groups of members. Maybe. It's more than either group alone.
But if I check both "Not Confirmed" and "Banned", I get a list which appears to be only a subset of the Banned members, none of whom also show as Not Confirmed (of course). I have no idea what it means.
And if I check both "Bouncing" and "Banned", it looks like I get a mixture of both - but not all of them. Strange.
Whatever it's doing, it is not consistent, and not sure if the result is correct. It might be neither the union nor the intersection of both choices.
(One might wonder why anyone would check both "Banned" and anything else. I thought I would get both. But it appears that I don't.)
I wonder if the menu should make it impossible to check off multiple choices when they don't work together. Or perhaps send the user an error, instead of a (semi-random) list of members, with no telling what it means.