Editors’ pick: Originally published Oct. 18.

If you were one of the 500 million people affected by the Yahoo data breach, you know firsthand that identity theft is everywhere.

According to a recent survey by Bankrate, 41 million adults have had their identities stolen in the U.S., and another 49 million say they know someone who has been affected.

And its not just your email account you have to worry about. It’s everything from your bank account to fraudulent voting this election to your tax return.

Tax-related identity theft occurs when someone steals your Social Security Number (SSN), files a tax return and claims your refund.

And whether the crook stole your SSN off your medical records or took your Form W-2, which reports your wages, right out of your mailbox at taxtime, is irrelevant.

Because you most likely will be completely unaware this has even happened until you try to electronically file your return and it gets rejected because your SSN only be used once.

Even worse, some victims have even gotten letters in the mail asking for more detail on their tax returns they never filed.

And while the IRS actively is cracking down on all this, it’s rampant. It’s even in the confines of the agency itself. Back in August, an IRS employee was sentenced to nine years and two months in prison for using her access to taxpayer information to lead a complex, multi-year, $1 million stolen identity refund scheme involving hundreds of victims.

And identity theft doesn’t just happen at tax time. The truth is, the off-season is when the scammers can catch you unawares.

So while the thieves may not have stolen your SSN (yet), they still will try to get money out of you.

If your phone rings and someone claiming to be an IRS agent is on the other line, stop speaking immediately.

The IRS will never:

• Call, text or email you. You will always get a letter first.
• Ask for credit or debit card numbers over the phone.
• Threaten to bring in local police or other law-enforcement groups to have you arrested for not paying.

If any of this happens to you, hang up and call the police.

(The IRS has a ton of information on its site about identity theft, so be sure to check it out here.)

But What If You are a Victim?

Call the IRS immediately. As painful as that sounds, call. There is a special hotline at 877-438-4338

You have to talk to someone at the agency. And an expert there will tell you how to proceed.

You will most likely have to file Form 14039 Tax Theft Affidavit and mail it to the IRS with a copy of your Social Security card and driver’s license.

What’s worse, you also will have to put a hard copy of your tax return now in the mail, because your SSN will be blocked by the e-file system.

Identify theft is a huge mess, because it affects everyone; it is not discriminatory. And unwinding the damage sometimes can take years.

So be on your guard at all times. Filing a tax return is onerous enough. The last thing you want to do is have to fight a thief for your refund.

For more tax tips, check out TheStreet’s Tax Center