A debt collector may only contact you between 8am and 9pm unless you agree otherwise. He may also not contact you at work if he knows your employer does not approve. If you have an attorney he must contact him, instead of you. If you do not have an attorney they are allowed to contact other people, though not more than once, to find out your where abouts and contact details but they may never reveal that you owe money.
After a debt collector contacts you, he must send you a notice within 5 days giving details about your debt. If within 30 days of receiving the notice you send a letter stating that you do not owe any money he may not contact you unless he can prove otherwise.
Debt collectors may not harass anyone they contact by way of threats, harassing phone calls, verbal abuse or by revealing confidential information.
They may not make false or misleading statements such as misrepresenting themselves and implying anything other than what is fact.
If you want a debt collector to stop contacting you, you can send a letter asking him to stop after which he is not allowed to contact you anymore.
You have the right to sue a debt collector if you feel he has violated the law within one year of the violation.