You don't have any problem if you don't remove addedby/addedate from baseforum!

But it's better if you remove because you are always this two properties everytime you call something from BLL.

It's a waist of information!

To alert my users I use a sessionvar and a javascript alert :)

I use the sessionvar because when the alert shows up (if there are any PM's) i save some value in this sessionVar.
With that The user only need to see it one time!