'We have taken steps to implement extra security processes requiring additional authentication for access to those HP accounts as well as other measures to prevent unauthorized use,' she said without elaborating.

After the theft, Fidelity contacted the three principal credit reporting bureaus to advise them of the situation and arranged for those affected to enroll in a free credit monitoring service. The service includes credit monitoring, a copy of their credit reports and notification of activity.

'If we conclude an unauthorized transaction has taken place in [an individual's] Fidelity account as a result of this incident, we will reimburse them for account losses connected with the unauthorized transactions,' Crowley said.

News of Fidelity's laptop loss comes amid heightened debate over a national breach disclosure law now under debate in Congress. The bill, which was recently passed by the House Financial Services Committee, is known as the Financial Data Protection Act of 2005 (H.R. 3997) and is designed to give financial services companies such as Fidelity a national standard for securing sensitive personal information and notifying consumers in case of a data breach.

A highly controversial provision in the bill would allow companies such as Fidelity to notify consumers of breaches only if they think there is a reasonable risk of actual harm resulting from the breach.