I don’t know why attempts continue to be made to collect these debts. The Statute of Limitations and is an affirmative defense. I think that it ought to be allowable to collect such debts, even thru suit, until the defense is asserted. However, the current jurisprudence disagrees with that position.
As such, attempting to collect time barred debts, even just with letters and phone calls, invites FDCPA suits. There is a split among the circuits right now about whether or not such action is per se an FDCPA violation. Here is the latest case on the subject.