For some time, the government has been working through the aftermath of the Office of Personnel Management hacking event that compromised the highly detailed, sensitive information of as many as 22 million people. In what experts are considering a separate data breach, the National Guard has announced its database has also been compromised.

The information that was inadvertently made accessible by a contract employee is believed to include names, addresses, Social Security numbers, birthdates, and more on “all current and former National Guard members” going back to 2004. It’s important to understand the reactions in this event, as well as the steps that individuals should take. This has been determined to not have been a hacking event, but would fall more into the category of what experts call an accidental internal data breach. The contract employee transferred the files containing the sensitive information to a non-accredited data center, which does not offer any indication that anyone accessed it or has malicious intent. It was simply a matter of the data center not having prior approval to receive that level of information.

No one has clarified yet if the file transfer was even requested by the data center or its employees. However, in this climate of data breaches and identity theft, the National Guard isn’t taking any chances. The affected individuals have been informed of the event, and a website and a call center have been set up that will let Guardsmen and Guard veterans check their credit reports, find identity theft prevention tips, and report any strange activity involving their private data.

Some of the strange activity that affected victims—or anyone who’s ever been the victim of an intentional or accidental data breach, for that matter—should watch for will include new lines of credit or new bank and credit card accounts, any signs of other employment being assigned to their Social Security numbers, medical bills or health insurance statements for treatment they never received, even warrants for their arrest should it go that far.

It’s also vital that anyone impacted by a data breach of any kind be watchful of their tax returns and file as early as possible in order to avoid being the victim of tax refund fraud next year. Anyone who’s already been a victim may also be eligible to place free alerts and freezes on their credit reports, which should prevent unauthorized people from opening new lines of credit.