Quote from the BBB:
DEBT COLLECTION
"Under the Federal Trade Commission's Fair Debt Collection Practices Act, collection agencies may not use any false, deceptive, or misleading representations or means to collect debts. They may not harass, oppress, or abuse any person while attempting to collect a debt. A debtor may be contacted between the hours of 8 am and 9 pm as well as at work unless instructed not to. Collectors cannot tell or discuss with others the debtor's personal finances."
"Consumers should be aware that debt collection is a civil issue and collection agencies are not empowered to issue arrest warrants. Consumers should also be aware that collection tactics such as impersonation of government officials or threat of arrest are violations of the Fair Debt Collection Act"