The U.K.-based Nationwide Building Society has been fined $1.9 million by the Financial Services Authority (FSA) over the theft of a laptop from a Nationwide employee’s home which contained confidential customer data.

FSA was particularly upset that the man had put details of nearly 11 million customers on his computer and that Nationwide did not start an investigation until three weeks after the theft occurred.

“Nationwide is the UK’s largest building society and holds confidential information for over 11 million customers,” said Margaret Cole, director of enforcement at the FSA.

“Nationwide’s customers were entitled to rely upon it to take reasonable steps to make sure their personal information was secure,” she added.

The building society would not say if the employee in question had been terminated or otherwise disciplined.