Dive Brief:

• The United States Postal Service revealed Monday that hackers have stolen sensitive data like Social Security numbers, birth dates, addresses, and other information, mostly from its employees.

• A file containing the data was compromised sometime in September and law enforcement, led by the FBI, and outside experts are still investigating and shoring up systems.

• Some customers who used the call center may have been vulnerable and should be on alert, but no one using the USPS.com website or post offices is affected.

Dive Insight:

Some sources believe that China is behind this attack; investigators have tied Chinese officials to breaches at other government agencies and contractors. But the real takeaway, as with every major breach, is the evidence that computer and Internet-based activities are vulnerable, and retailers — or anyone connected to the Internet — must be less sanguine about that. This hack was quite democratic, affecting the postmaster general as well as letter carriers and employees of the inspector general's office.

“It is an unfortunate fact of life these days that every organization connected to the Internet is a constant target for cyber intrusion activity,” Postmaster General Patrick Donahoe said in a statement. “The United States Postal Service is no different. Fortunately, we have seen no evidence of malicious use of the compromised data and we are taking steps to help our employees protect against any potential misuse of their data.”