What did the court decide in Obduskey v. McCarthy & Holthus LLP?
Answered for: US
In our view, the last sentence does (with its §1692f(6) exception) place those whose "principal purpose . . . is the enforcement of security interests" outside the scope of the primary "debt collector" definition, §1692a(6), where the business is engaged in no more than the kind of security-interest enforcement at issue here—nonjudicial foreclosure proceedings.
The Court held that a business doing no more than nonjudicial foreclosure is not a 'debt collector' under most of the FDCPA, except for the limited purpose of section 1692f(6). The sentence above is the court in its own words.
This answer is true in US and nowhere else on this site. Another jurisdiction is another answer, or an honest gap: see what has been read for US.