OAK CREEK, Wis. — Guardian Credit Union has become the latest credit union to disclose a data breach that may have exposed Social Security numbers, driver’s license information and financial account information belonging to some individuals.
The $295-million Guardian CU reported the incident to the Massachusetts Office of Consumer Affairs and Business Regulation on Aug. 6, ClaimDepot reported. The filing identified nine Massachusetts residents as affected, although the total number of people affected nationwide was not disclosed.

According to the credit union’s filing, information potentially exposed in the incident included:
- Social Security numbers
- Driver’s license information
- Financial account information
No Information on How Breach Occurred
Guardian Credit Union did not provide details about how the incident occurred in its notification to affected individuals.
The credit union said in the notification letter that it was “unable to provide further details about the nature of the event” because of requirements under Massachusetts law. It instead directed affected individuals to a dedicated assistance line for more information.
According to the notification letter cited by ClaimDepot, Guardian Credit Union discovered suspicious activity and began an investigation with assistance from third-party forensic specialists to determine whether its network was secure.
After completing that investigation, the credit union hired another third party to conduct what it called “a comprehensive and time-consuming review” of information that may have been at risk.
Guardian Credit Union then conducted additional work to verify the affected information and identify mailing addresses for individuals who needed to be notified.
Credit Monitoring Offered
Guardian Credit Union is providing affected individuals with 24 months of complimentary credit monitoring and identity protection services through Experian IdentityWorks.
People who received notification letters can enroll through Experian using the activation code included in their letter. Enrollment must be completed by the deadline specified in each individual’s notification.
According to the notification letter, the Experian IdentityWorks membership includes an Experian credit report upon enrollment and daily credit reports for online members. It also includes monitoring of Experian, Equifax and TransUnion credit files, access to identity restoration specialists and $1 million in identity theft insurance.
Identity restoration assistance will remain available after the membership expires through Experian’s ExtendCare program, according to the notification.
Guardian Credit Union established a dedicated assistance line for people with questions about the incident. The line is available Monday through Friday from 9 a.m. to 9 p.m. Eastern time, excluding U.S. holidays.
Affected individuals also can contact the credit union at [email protected].
“We take the privacy and security of personal information in our care very seriously and sincerely regret any inconvenience or concern this event may have caused,” Guardian Credit Union said in its notification letter.



