Image via AP.

Last month, about 12,000 Aetna customers across the US were sent letters regarding their health benefits and access to HIV medications with a clear window cut out of the envelope that exposed their status to anyone who laid eyes on it.

The Washington Post reports that the Legal Action Center and the AIDS Law Project of Pennsylvania have released a letter requesting that Aetna immediately cease and desist these mailings, and take measures to assure that nothing like this ever happens again. According to Bloomberg, the window’s design exposed patients’ names, address, and within the first visible sentence, information on their options for receiving HIV prescriptions. Lawyers from both organizations write that the fear of being involuntarily exposed came true for several recipients:

These privacy violations have caused incalculable harm to Aetna beneficiaries. A number of the individuals who contacted the above-referenced organizations reported that family members and neighbors learned their confidential information regarding their use of HIV medications as a result of Aetna’s breach.

The attorney’s have collectively received 23 complaints, but there will likely be more, as Aetna started notifying patients of the error after becoming aware of it on July 31. CNN got a hold of the form letter that notified customers while promising a correction of the issue:

Upon learning of the issue, we took immediate steps to investigate what happened. We then confirmed that the vendor handling the mailing had used a window envelope, and, in some cases, the letter could have shifted within the envelope in a way that allowed personal health information to be viewable through the window. On August 2, 2017, we determined this incident may have caused a breach of your protected health information. Regardless of how this error occurred, it affects our members and it is our responsibility to do our best to make things right. We will work to ensure that proper safeguards are in place to prevent something similar from happening in the future.

According to lawyers at the Legal Action Center, customers have also logged complaints with the Office of Civil Rights of the Department of Health and Human Services.