You or someone you know with either a very old debt or a non existent debt may have gotten a call from a company who has purchased the debt claiming to be not a collection agency but an arbitration firm. They usually will say that they are with the litigation department and that they will be sending someone out to serve you with papers about a lawsuit. They will use all these technical legal terms to get you scared enough into paying the debt. Each state has a different statute of limitations for debt but where I live in NH it is 3 years. This means after this time they cannot take you to court over this and these companies know this. They just want you to make a payment arrangement because that way it reopened the statute so NEVER do this.
No matter what these people will tell you you are not going to go to jail for not paying a debt even if it is valid. Chances are good that these people contact you just to scare you with no intentions on suing you. If you happen to answer your phone when they call just tell them you are expecting legal papers by tomorrow and if you don't have them you will file suit against them for violating the Fair Debt Collection Practices Act. This will sometimes make them go away because they figure you know what your talking about. If this continues report them to the FTC and contact an attorney if you want to take it to court. Violations of the FDCPA are a minimum of a $1000 fine for each violation. If they are severe enough it will cost them much more and possible criminal action will be sought.
Times are tough for people and these collection agencies that purchase very old debt know that if they follow the law its going to be hard to get people to pay. That's why they represent themselves as an arbitration firm because they feel that once people hear that they are going to be more willing to pay. This is considered extortion which is illegal and NEVER let anyone do this to you. If you have been harassed by a company like this then your best bet is to contact an attorney. If this company is making threats about hurting you or saying that they are police officers then you want to contact your local police station.