Two customers have filed a class action lawsuit against Fidelity Investments over a data breach in August, alleging negligence and invasion of privacy.

The Boston-based wealth manager announced last week that a hacker had created two accounts, obtaining personal information from nearly 77,100 customers.

In a lawsuit filed later last week in U.S. District Court in Massachusetts, Yaakov and Seth Gluck, who live in Spring Valley, New York, alleged that the hacker stole Social Security numbers, financial information, names, numbers and addresses.

Thanks to Fidelity's “failure to protect the personal information of breach victims, cybercriminals were able to steal everything they might need to commit nearly every form of identity theft imaginable, wreaking havoc on the financial and personal lives of potentially millions of people.” The complaint alleges.

Fidelity caused harm to the plaintiffs by “failing to take reasonable and appropriate measures to ensure that their computer systems were protected” and by failing to take reasonable steps to prevent and stop the breach, detect it in a timely manner and failing to keep promises to protect customers' personal data, the Glucks claim.