Using sentences verbatim from a referee report without attribution
If you are the reviewer, just let the editor know the plagiarism problem.  Hopefully this is prior to the paper getting out.  

A reasonable outcome would be for the text to be paraphrased AND a more specific acknowledgment made "one reviewer for specific content in section 3".  I would gently suggest such to the editor.  "Please go ahead and take whatever action you feel best as editor, but I suggest modify the text and make a more specific acknowledgment".

An alternate outcome is to leave the text as is and become a co-author,  (If the contribution meets the threshold.  Perhaps it might on a review or theory paper.)  But I would not be seen as pushing for such an outcome and it comes with issues of its own (now you are tied to the rest of the paper).

If the paper was already published, I would still let the editor know, but I would copy the editor in charge (since the subeditor let the plagiarism of the reviewer text get by).  It's not the end of the world for the subeditor but he needs to be mildly held to account also.

All this assumes it is not some junky journal.  If it is and they don't take action, you should obviously stop reviewing for them (and shouldn't review for junky journals regardless).  If it is a conference proceedings the issue is a little trickier since they don't really have all the same systems and editorial strengths, but I would still notify both subeditor and editor of the problem.