While moving (instead of deleting) my duplicates, I noticed that my internet access light was on constantly. So I disconnected, and DC instantly stopped moving files. It will not process as long as there is no internet access.
What is going on? Is it sending a copy of my files to some unknown site?
No- it just uses standard windows api methods to move files, so I've no idea why your light is on, unless you were moving to a network drive or some other windows background process is at work