Langdon & Co. CPA LLP Data Breach — Class Action Review

Langdon & Co. CPA LLP is a professional accounting, tax preparation, and financial advisory firm serving individuals, closely held corporations, partnerships, and non-profit entities. Because the core function of an accounting practice involves managing the complete financial profiles of its clients, Langdon & Co. CPA LLP routinely collects, processes, and stores an immense volume of deeply sensitive personal and corporate data. This includes exhaustive records necessary for tax compliance, auditing, and wealth management, making the firm a centralized repository of high-value personally identifiable information that cybercriminals actively target for exploitation.

In 2025, Langdon & Co. CPA LLP reported a significant data security incident to the New Hampshire Attorney General's office. While the precise vector of the attack continues to be investigated, incidents of this nature in the accounting and financial services sector typically involve sophisticated cyberattacks such as ransomware deployments, unauthorized network intrusions, or credential harvesting that compromises internal databases and file-sharing environments. CPA firms are prime targets for malicious actors seeking to intercept continuous streams of financial correspondence, client portal data, and archived tax returns.

The breach exposed a vast array of critical personal information, creating severe, long-term risks for affected individuals. Because of the nature of the firm's work, exposed data frequently includes Social Security numbers, dates of birth, full names, banking and routing numbers, investment portfolios, and comprehensive copies of prior-year federal and state tax returns containing W-2 and 1099 details. When this information is compromised, victims face an immediate and elevated threat of sophisticated tax fraud, identity theft, unauthorized credit applications, and financial account takeover, as cybercriminals weaponize tax documents to file fraudulent returns and intercept government refunds.

As a custodian of sensitive financial and personal data, Langdon & Co. CPA LLP had strict legal and professional obligations under state data protection statutes and the Gramm-Leach-Bliley Act, where applicable, to implement robust administrative, physical, and technical safeguards. These regulations require firms to maintain continuous network monitoring, encrypt sensitive consumer data at rest and in transit, and enforce rigorous multi-factor authentication protocols. The occurrence of a widespread data breach strongly suggests a potential failure in these baseline security duties, raising serious questions regarding whether the firm's cybersecurity posture was adequate to defend against foreseeable digital threats.

Receiving a data breach notification letter from Langdon & Co. CPA LLP is a formal acknowledgment that your private financial records were compromised due to corporate negligence, and it establishes the legal standing necessary to participate in a class action lawsuit. You do not need to wait until financial theft occurs to take legal action; the increased risk of future harm and the expense of mitigating identity theft are recognized injuries under the law. Our firm is currently investigating potential claims on a contingency fee basis, meaning there is never any out-of-pocket cost to you, and we only collect a fee if we successfully recover compensation on your behalf.