[cycomanic]

Maybe this is what you are saying, but doesn't "... have been watched" imply that the being watched is finished, compared to have been being watched" implies a that the watching is (or might be) still ongoing, i.e. the use of simple past vs present perfect continuous(?)

[lmm]

No, "have been being watched" is the past progressive. It implies that the being watched was an ongoing thing at that time, not that it's still continuing.