I have been doing a lot of beta review, and often that calls for using the "canned comments" for recommended deletion. It seems that a lot of users are confused and getting quite offended that I am critiquing their posts from upwards of two years ago.
I suspect I've gotten around 20 messages from different users calling me a troll for digging up posts from the past. I'm fine to defend myself, but as this user mentioned it might be nice if there was some indicator that the comment was generated by the beta review process. This way the user would understand that my critique is nothing personal but just a side effect of the process.