Cavalry Portfolio phishing for identity information; attempted identity theft; trying to extort money from me for someone else's debt Hawthorne New York

I received a letter stating I owed $532.74 to Cavalry as a debt collection agency for Sprint. They asked for my checking account number, and said they would make an electronic transfer. I sent a return letter disputing the amount, asking for their proof. They returned a receipt from Sprint for a guy with the same first and last names, but with a different middle initial, and with an address totally unknown to me. My next letter to them, indicated they had the wrong party, check out the middle initial and address,which were not mine.

They replied with another letter saying my identity had been stolen and that I now needed to provide them with my social security number, driver's license number, etc. I knew no legitimate business would expect me to return this info, and thank God for this website and the poor folks that had trouble ahead of me. My credit is clear so far, but this is an unscrupulous business practice. If I had given them my information, I feel confident they would have stolen my identity, placed a damaging debt on my otherwise perfect credit report, that I would then have to work at disputing.

How can a "legitimate" business like this, get away with identity theft? How many people does it take to be victims before they are stopped?

Robert
Houston, Texas
U.S.A.