I sometimes accidentally move my capture lines, trying to move something else, and this cannot be undone. So my suggested solution are:
1. ability to undo it
2. ability to lock them
3. divide the one created in the master pages (that propagate thought the all document editable only in master itself) from the ones in the standard pages (that exhist only in that page)
Operating System: Windows 7
Version: 188.8.131.52 release
Looks like a valid enhancement to me.