Something that jumped off the list at me: Adding users to an existing private topic opens a wide gamut of privacy concerns.
I would never ever post to or even read a private topic if I knew that another person could be added afterwards.
I agree 100%, the only way I would think of liking it is if only the person who created the topic can add, a notification in the pm was made that xxxx was added, and the newly added cannot look back through the topic.
We add people to PM's roughly three times a month as a matter of course - but only as an admin function which cannot be executed except by exactly two admins, which is to say not all admins can do it.
We only add them if everyone in the PM agrees and the PM starter requests it.
To give you some idea of our traffic so you can compare the requests to busy, we average about 450 - 500 posts a day. PM count is roughly 20 - 30 percent of our post count. This is our off season - it will start picking up now and will likely peak in February at around 1,500 posts a day.
For whatever it is worth, we compartmentalize what an Admin can do by using MySQL Workbench and only issuing scripts to who we want to have scripts. Only one person is allowed to write new scripts and only two have them all, for control and security purposes.
I would think that Sir Dude and Gizmo know exactly what I am talking about.
