If this is done to evaluate coaches, I hope it is done in the open, using evaluation forms, not by spying on and evaluating coach/student interactions without permission. We all do it a little when selecting our own coaches, but affecting pay scales by watching one day's interaction with a few students - ouch.
I bet those of you who are coaches would prefer an open system, in which you know what is going on, and can see the results and the comments people make.
--just my opinion.