You must be a Mastercard cardholder to use this free service. I signed up. It seems like a good service. Certainly the price is right:
https://www.mastercard.us/en-us/consumers/payment-technologies/id-theft-protection.html
The service covers a variety of personal information items. All of them except for social security number may be selected by you or not for monitoring, on an a la carte basis. Notice of activity is provided to you via e-mail, or you may choose instead to log into your free account for an instant readout regarding how things stand. As with all monitoring services of this sort, no news is good news.
If you are not a Mastercard cardholder, I know Discover Card offers a similar free service. I do not have the Discover Card so I'm unable to provide information about their service based on personal experience. However, more information is available here:
https://www.discover.com/credit-cards/member-benefits/security/ssn-newaccount-alerts/
Visa? I'm unaware of free service offered by Visa to its cardholders similar to that offered by Mastercard and Discover. If you are aware of such a free Visa service, please post.