Letter to the editor: According to your last edition’s anonymous article, we should all be required to carry identification cards and show them on demand.
Conclusion
This opinion is wrong. rephrase: We should not be required to carry ID cards and show them on demand.
Evidence (after all)
The writers of the article should not have asserted that the right to remain anonymous was trivial, unless they were prepared to put their names to that assertion.
Evaluate
This author's evidence doesn't seem to have anything to do with her conclusion. She's trying to convince her audience that we shouldn't be required to carry ID cards and show them on demand.
Why shouldn't we? Would it be too hard to disseminate ID cards to everyone? Would people too frequently forget to have their ID card on their person and get in trouble as a result? Would authorities employ their power to stop people and demand to see their ID cards in some way that would target or terrorize subsets of the population?
She doesn't say anything like that. In fact, she doesn't say anything about this Plan at all. There's no discussion of what positive or negative ramifications would result of installing a policy of mandatory ID cards.
Instead, she just says something about the people who wrote the article.
Attacking the source of ideas rather than the content of the ideas is one of the 10 famous flaws, called Ad Hominem. In almost all examples of Ad Hominem, the author tries to dismiss some idea because the source of the idea either (1) has a biased interest in the matter, or (2) has conflicting past behavior.
This is a case of #2. The author is saying the person who wrote this article behaved in a way that's inconsistent with their claims (they wrote an article anonymously while agitating for a policy of everyone being required to show their identification).
Goal
Look for an answer saying that this author failed to respond substantively to the article's position, and that it instead tried to disqualify the position based merely on the fact that the writer behaved in a way that seems at odds with their position.