Wells Fargo, already in various degrees of hot water over using customers’ personal information to open accounts without their knowledge or consent, now has another black eye over the bank’s security of its customers’ information.

The New York Times reported over the weekend that Wells Fargo accidentally leaked the sensitive personal information of approximately 50,000 of its wealthiest clients to a former employee who’s suing one of the bank’s employees for defamation.

Here are the details from the Times report:

When a lawyer for Gary Sinderbrand, a former Wells Fargo employee, subpoenaed the bank as part of a defamation lawsuit against a bank employee, he and Mr. Sinderbrand expected to receive a selection of emails and documents related to the case.

But what landed in Mr. Sinderbrand’s hands on July 8 went far beyond what his lawyer had asked for: Wells Fargo had turned over — by accident, according to the bank’s lawyer — a vast trove of confidential information about tens of thousands of the bank’s wealthiest clients.

The 1.4 gigabytes of files that Wells Fargo’s lawyer sent included copious spreadsheets with customers’ names and Social Security numbers, paired with financial details like the size of their investment portfolios and the fees the bank charged them. Most are customers of Wells Fargo Advisors, the arm of the bank that caters to high-net-worth investors.

According to the report, the leaked information came via the discovery process in Sinderbrand’s lawsuit, and because the files came with no protective orders or confidentiality agreements, Sinderbrand could theoretically release the information to the public or include in in their lawsuit filings, which would also become public record.

And according to the Times report, the information that was leaked is sensitive.

Again from the Times report:

The New York Times was shown large portions of the data and confirmed that it included what appeared to be clients’ names, unredacted Taxpayer Identification Numbers, assets under management, portfolio performance, mortgage information and details on 529 education savings plans.

One file, for example, contained details on the holdings of a well-known hedge fund billionaire who had at least $23 million invested through Wells Fargo Advisors.

Click here or below for much more from the Times.