There are around 200,000 personnel who routinely use the database.
"Central records are not maintained of this information and thus it is not possible to answer your request without collecting this information," the DWP told Computer Weekly in answer to a Freedom of Information request. It said collecting the information would be too costly.
The CIS is the biggest central government database of all of our information. How it can treat our data with such little respect beggars belief - over to you ICO.