Here's a puzzle: I do WHOHAS UID(0) and get a list of ACIDs. Some of them are entirely numeric, so I check curiously. The ACIDs exist—they're customer IDs, no way they should have UID(0)—but the LIST command doesn't show that they have an OMVS segment, much less UID(0).
I experimentally do REM(acid) UID(0) and TSS says the remove is successful—it doesn't complain that the ACID didn't have UID(0) in the first place. But when I do the WHOHAS again, the same ACID is still listed there.
Can anyone divine what's going on here? I know Unix hardly at all, but I have a vague notion there's maybe a system file somewhere that specifies extra superusers...? Reaching for straws, I know. But I want to investigate this; it sounds like an exposure.