1. A private meta-data integration method for an activity-centric collaborative environment, the method comprising: generating in an activity centric collaborative environment, a multiplicity of activity threads, each comprising a multiplicity of activity objects each comprising each of messages, chats and files exchanged among members of a team collaborating in a group project; associating each of the activity objects of the threads with corresponding meta-data indicating a creator, and further associating a subset of the corresponding meta-data with a privacy flag; selecting one of the activity threads on behalf of a particular member collaborating in a corresponding group project for the selected one of the activity threads; displaying the selected one of the activity threads in an activity map of the activity-centric collaborative environment for viewing by the particular member; and, for each object in the selected one of the activity threads, loading corresponding meta-data and displaying the loaded meta-data in the activity map unless the corresponding meta-data is associated with a privacy flag and on condition that the corresponding meta-data is associated with a privacy flag and the particular member is identified as being the same as a creator of of corresponding object, displaying the loaded meta-data in the activity map, but otherwise on condition that the corresponding meta-data is associated with a privacy flag and the particular member is identified as being different than the creator of the corresponding object, not displaying the corresponding meta-data.