I have sadly been in the rare position of listening to a CVR from an accident I was involved in. We sat with the AAIB and listened from the moment the unit was powered up (when P2 got into his seat) until impact, when the G switch stopped it. P2 was a senior management pilot and friend, some of the things we discussed would have made my mother blush (anybody who's met her would be surprised to know she could) and some things were about the company, and some things were intensly personal (divorce and all that goes with it) The key times (top of drop to impact) we had a sterile cockpit and the SOPs were followed to the letter. When the report came out we were in the clear, but if the company had heard the conversation I have no doubts unemployment would have come swiftly and with a lot of malice.
At the same company there was a rumour that the man who monitered CVRs for maintenance purposes had repeated parts of conversations. I do not know if it was true, but afterwards the erase button was always pressed.
I am totally against company monitoring of CVRs. We have to be trusted to do our jobs, as we trust those who maintain our aircraft and keep them apart in flight. If the book says "Sterile cockpit below ???" then trust us to do that. If at the court of enquiry we have not followed procedure then hang us out to dry. We have to learn from the mistakes of others, if we do then CVR monitoring is utterly unnecessary.