For Twitter you can use the UserName parameter of the GetStatuses call to load tweets from a specific user.
For Facebook you can use the Profile parameter of the GetFeed call to load a feed from a specific user. Note that the Facebook API does not allow access to accounts that haven't authorized the your Facebook App and also limits access to accounts that have authorized the Facebook App.
This technique is demonstrated in the respective demos that are included with TMS VCL Cloud Pack