Dorsey Thornton & Associates (a.k.a. DTA Investigations) - They are scammers. They make claims that you owe for online payday loans that were never taken out, threaten to have you arrested for check fraud, and so on. They have an 'F' rating with the BBB, and are not licensed in most states to collect on debts.
If you have ever applied for an online payday loan, regardless of whether you took one out or not, chances are that your personal details (e.g., name, address, SSN, drivers license #, place of employment, references, etc.) have been sold to numerous scam artists who will try to scare you into paying on made-up debts.