In a case of credit card debt, when the account has gone to a collection agency, is it legal for them to call the owner of the account's neighbors and discuss the account,etc. with them,on the pretense of being unable to make contact? If not, who can this be reported to?

No it is not. That would be a violation of the Fair Debt Collection Practices Act.

They CAN, though, call a neighbor to ask questions about you.

Report violations of the FDCPA to the FTC and your State Attorney General.

... but before you do, talk to a manager at the collection agency and tell them of the violation and offer to be mum about it if they'll pay the bill for you. I've seen it work!

If you have a need to contact the neighbor about some one's else debt... let stop now... you have valid their right to privacy... to collect a debt there is the courts or continued telephone calls... in order to make arrangements... you will be harassing the debtor...

Now there are certain laws in each about debt collection... for instance, no automatic calling in the state of Texas... no calling of names by the collector... more then three calls a day is considered harassment... if there are problems associated with this then contact the Department of Consumer Affairs in your state and the Attorney General Office for further information...