Your Social Security number may have been leaked. Should you freeze your credit?

(NEXSTAR) – News surfaced this week of a major breach in which hackers claim to have stolen the personal data of every American, including birthdays and Social Security numbers.

The data, exposed in an April breach, appears to come from a background check company and could include as many as 2.7 billion personal records. It's now the subject of a class action lawsuit and causing renewed concern among people who fear they've been hit.

While the scope of the leak is astounding, it isn't breaking entirely new ground, explained Cliff Steinhauer, director of information security and engagement at the National Cybersecurity Alliance. It's the latest in a series of privacy breaches that have left almost all of us exposed.

"If your data hasn't been breached in the last couple of years, you're probably in the minority. And if this breach now has breached your data, then welcome to what the rest of us are dealing with," he said.

The chief concern when your birthday and Social Security number are compromised, Steinhauer explained, is identity theft. Those are two key pieces of information bad actors can use to open new lines of credit.

"In today's environment, that's still all you need to set up most types of accounts – getting loans, setting up bank accounts, renting or buying a car, those types of things."

And if you're not paying close attention, identity theft may happen without you knowing.

The best way to protect your finances is by freezing and monitoring your credit. Freezing your credit with all three major agencies – Equifax Experian, and TransUnion – means no one can open a new credit card or take out a loan in your name. If you ever want to open a new card or account, you'll just need to unfreeze your credit. The process takes a few minutes and it's free.

Even people whose identity hasn't been stolen can freeze their credit, the Federal Trade Commission says. While frozen, you'll still be able to use your existing cards and accounts, and it won't interfere with applying for jobs, renting a new apartment or buying insurance.

"A fraud alert would add extra layers of authentication and make sure that the person applying for credit is the person who owns the credit," Steinhauer said. "So they typically will call you and ask you extra questions to validate that you are who you say you are."

You're also entitled to a free credit report every year, which Steinhauer recommended looking at to make sure there isn't anything fishy going on.

You can pay for identity theft monitoring services as well, but there are even more free steps you can take to lock down your identity. Using unique passwords, multi-factor authentication (when available), and making sure you're watching out for phishing scams all help.

"I don't want people to think that there's nothing they can do to protect themselves or that it's not worth it to protect themselves," Steinhauer said. "You do need to take steps to protect yourself. You do need to make it more difficult for attackers to be successful with your data. If everybody listened to my advice, the attackers, many of them wouldn't be able to continue, and it would take a lot more effort and time and money to have an impact on people's lives. So let's not make it easy."