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If the original creditor already sold off the debt to the collection agency and then removed their name from your credit report, the collection agency can still collect the debt, provided they can validate it. However, if they cannot validate the debt, they cannot sue you and bring judgment against you.

what carol said is not really true--they CAN still sue you and often do. The law does not forbid them from suing---it allows you to force them to prove their claim. If you do not challenge their complaint or exercise your rights, you lose those rights. They can sue you without a shred of proof and win--and junk debt buyers file suits by the dozens each day in the hopes that the defendants wont show up. You must now challenge what they are claiming and force them to prove it.....or else you ask that the court dismiss their case against you with prejudice.