If you get a phone call from your bank and a representative tells you there’s an issue with your account, it’s a pretty safe bet that you’ll sit up and take notice. After speaking to the representative for a few moments and verifying your account holder information, you might be offered some options if there’s a payment or minimum balance issue.

Obviously, you’d want to resolve the matter as quickly as possible, even if it meant transferring money from another account or paying funds into your account by credit card. There’s just one problem: that helpful young man who took the time to call you about the issue doesn’t work for your bank. He might not even be in this country, let alone working from an office at your financial institution.

Using a technique known as “caller ID spoofing,” scammers are able to alter their phone numbers to make it appear that they work for your bank, your credit card company, the IRS, even your local police station. What citizen wouldn’t follow instructions when the police call to inform you that you owe a speeding ticket fine, or that your loved one is in jail and you can post his bail over the phone via credit card?

That’s the unfortunate reality for many victims of phone scams, which is why Pennsylvania State Representative Karen Boback is working to introduce legislation in her state that will make it a crime for unauthorized agencies or individuals to spoof their information in order to appear to be someone else on your caller ID. The bill, House Bill 391, would make it a misdemeanor to change your data for this kind of purpose. It does not prevent people from blocking their data, though, which is an important distinction.

In the case of a blocked caller ID, or “unknown number” message on your screen, you still have no way of knowing that the caller is a scammer, but at least you would know that your bank or the IRS will never call you from a blocked number. There’s an important lesson here that underlies this crime, though, and that’s the willingness to give out personal information to strangers.

No matter what the number says on your caller ID, there is never a valid reason to give someone your account number, your Social Security number, or any other identifying information if they contact you. If you were the one who initiated the call, you might still have reason to be cautious when it comes to supplying others with your information. Finally, there is almost no conceivable reason to make a payment over the phone to an unsolicited request. If someone contacts you for a payment, hang up and call back using a known, verified phone number for the company or agency.