Again it happened, out of the blue. This time about 1000 new profiles landed on my watchlist that I am desperately trying to manage and reduce.
I have written to the person who wrought this havoc, and asked her to globally undo. But in the meantime, I have found that by sorting the watchlist on Edit Date I have found that most of the offending entries happened on a certain date, and I could identify the ones I didn't manage in that there was no "M" (as Vincent kindly pointed out above).
So, an hour out of my life, and I hope I've removed myself from these trusted lists that mean nothing to me.
In the bulk removal tool, when requesting to provide a list to remove yourself, could we please have the same "M" indicator displayed?