Owing money isa civil matter, not criminal. And threatening is a big no no, it breaks the FDCPA laws.  Most of these are extortion scams, hoping to scare you into sending them money, usually on a green dot card (big red flag).

Please do file reports with the FBI, your state attorney general and Department Of Justice,FTC & FCC..

http://www.ic3.gov/default.aspx
http://www.fbi.gov/
https://www.ftccomplaintassistant.gov/#&panel1-1
https://esupport.fcc.gov/ccmsforms/form1088.action
http://www.consumerfinance.gov/complaint/

Also read up on the laws and your rights:

http://800notes.com/arts/Jb8EW-eDhQA/harassin ... ou-need-to-know
http://www.ftc.gov/os/statutes/fdcpajump.shtm
http://www.consumerfinance.gov/askcfpb/search ...
http://www.consumer.ftc.gov/articles/pdf-0096-fair-credit-reporting-act.pdf

And see:

http://800notes.com/forum/ta-86217073a9c8dad/ ... 077595690349410
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http://www.consumer.ftc.gov/articles/0258-fake-debt-collectors
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http://www.deadiversion.usdoj.gov/pubs/pressreleases/extortion_scam.htm
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A Collection Agent May Not…

Here are the top 11 actions prohibited by the The Fair Debt Collection Practices Act:

Misrepresent Him or Herself

A debt collector may not misrepresent himself as an attorney or law enforcement officer.

Use the Telephone to Annoy or Harass

A collection agent may not cause a telephone to ring or engage any person in telephone conversation repeatedly or continuously with an intent to annoy, abuse, or harass anyone at the called number.

Threaten Arrest or Lawsuit

A collection agent may not threaten a consumer with arrest. It may not threaten legal action that is either not permitted or not actually contemplated. In other words, a the threat of a lawsuit may be an empty one.

Use Abusive or Threatening Language

A debt collector may no use abusive or profane language in the course of communication related to the debt.

Publish a Bad Debt List

Publishing the consumer’s name or address on a "bad debt" list is prohibited.

Contact By Embarrassing Media

A debt collector may not communicate with a consumer by post card. It may not use any language or symbol, other than the debt collector’s address, on any envelope when communicating with a consumer by use of the mails or by telegram. A debt collector may use its business name if such name does not indicate it is in the debt collection business.

Contact a Consumer at Work

A collection agent may not communicate with consumers at their place of employment after being told this is unacceptable or prohibited by the employer.

Seek Unjustifiable Amounts

A debt collector may not demand any amounts not permitted under an applicable contract or as provided under law.

Contact a Consumer Represented by an Attorney

A collection agent may not contact a consumer after it learns the consumer is represented by a lawyer.

Communicate With a Consumer After Receiving a Validation Request

If a consumer sends a written §1692g response within 30 days, the collection agent may not communicate with the consumer until it mails the consumer the requested verification of original creditor's name and address.

Communicate With Third Parties

A debt collector may not reveal or discuss the nature of a consumer’s debts with third parties other than the consumer’s spouse or attorney. A collection agent may contact neighbors or co-workers only to obtain location information. It may contact a third party again if it has reason to believe the information the party provided previously is false.

Bills.com FDCPA FAQ

Below are questions Bills.com readers ask frequently:

Can a Collection Agent Call My Cell Phone?

Yes. However, if you tell the debt collector it may not use that number because it is a cell phone, it may not contact you again at that number.

I Keep Receiving Dozens of Calls From Collection Agents. Is That Legal?

No. Unscrupulous collection agents will use "block parties" or "office parties" where they contact a consumer, multiple neighbors, or co-workers telling them they need to reach the consumer on an urgent matter. This is not permitted under the FDCPA.

A Collector Says I Will Be Arrested if I Do Not Pay

This was a true statement before the US Civil War, but has not been true since. People may be arrested if an aggressive judge files a bench warrant for a person who does not appear at a hearing relating to a lawsuit regarding a debt. However, in that case, the offense is the failure to respond to a court order, and not the existence of the debt. As stated above, it is illegal under the FDCPA to threaten a consumer with arrest if the consumer does not pay the debt.
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http://dfi.wa.gov/consumers/alerts/cashnet-payday.htm
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Extortion Scam Related to Delinquent Payday Loans

Washington, D.C.
December 07, 2010  FBI National Press Office
(202) 324-3691

— filed under: Press Release

The Internet Crime Complaint Center has received many complaints from victims of payday loan telephone collection scams. Callers claim the victim is delinquent in a payday loan and must repay the loan to avoid legal consequences. The callers purport to be representatives of the FBI, Federal Legislative Department, various law firms, or other legitimate-sounding agencies. They claim to be collecting debts for companies such as United Cash Advance, U.S. Cash Advance, U.S. Cash Net, and other Internet check-cashing services.

According to complaints received from the public, the callers have accurate data about victims, including Social Security numbers, dates of birth, addresses, employer information, bank account numbers, and the names and telephone numbers of relatives and friends. How the fraudsters obtained the personal information varies, but in some cases victims have reported they completed online applications for other loans or credit cards before the calls started.

The fraudsters relentlessly call the victim’s home, cell phone, and place of employment. They refuse to provide any details about the alleged payday loans and become abusive when questioned. The callers have threatened victims with legal actions, arrests, and, in some cases, physical violence if they do not pay. In many cases, the callers harass victims’ relatives, friends, and employers.