How to find how and when particular account or user was created?
Account / user creation events can be found in:
BA Control Panel - System - Settings - Events
Particular event looks like the following:
Event # 97803
Event Type Account Created
Schedule Time 01-Jan-1970 07:00:00
Parameters AccountID=1000012; Originator=BM;
Here, "User" is the ID of the user, who initiated Account creation. If "-1" specified as a User, that means the action took place after processing API call, for example after placing Order from the Online Store.