Can a debt collection agency legally identify themselves a 'collection agency' when placing inquiries on your credit report when the debt in question was charged off over a decade ago?

Report a harassing collection agency?  Can new collection agency report old debt?  Can a collection agency call forever about a debt?  Can a creditot sell your debt to a collection agency?  Can collection agency pull credit report for outdated debt?  How can you clear your debt from the credit agency database?  Can a debt collection agency run a credit check on you without permission?  Can a debt be eliminated if the collection agency does not show up for court?  Can a collection agency purchase a ten year old debt and report it as a new debt?  You havent paid on a credit card in 9 years they have report the balance to CRA but now transferred debt to collection agency?  How can you make sure that your debt is paid to a collection agency you know about letterswhat if they dont send?  Can an old debt which is no longer on the credit report be purchased by a collection agency and reported again?  A debt you owed was 2500 it was charged off 3 years ago can the collection agency still collect on it legally?  After seven years can a collection agency place the same debt on your credit report under a different name?  Can a credit card that has been charged off and sold to a collection agency garnishee your SSI check?  Can a collection agency report the same debt more than once on a consumers credit report?  Can a collection agency still take you to court if you are in a debt relief program?